The Fourth Amendment Third-Party Doctrine

Congressional research reportJun 5, 2014

Ask Donna

What actually matters in this document.

Text

The Fourth Amendment Third-Party Doctrine

-name redactedLegislative Attorney

June 5, 2014

Congressional Research Service

7-....

www.crs.gov

R43586

The Fourth Amendment Third-Party Doctrine

Summary

In the 1970s, the Supreme Court handed down Smith v. Maryland and United States v. Miller, two

of the most important Fourth Amendment decisions of the 20th century. In these cases, the Court

held that people are not entitled to an expectation of privacy in information they voluntarily

provide to third parties. This legal proposition, known as the third-party doctrine, permits the

government access to, as a matter of Fourth Amendment law, a vast amount of information about

individuals, such as the websites they visit; who they have emailed; the phone numbers they dial;

and their utility, banking, and education records, just to name a few. Questions have been raised

whether this doctrine is still viable in light of the major technological and social changes over the

past several decades.

Before there were emails, instant messaging, and other forms of electronic communication, it was

much easier for the courts to determine if a government investigation constituted a Fourth

Amendment “search.” If the police intruded on your person, house, papers, or effects—tangible

property interests listed in the text of the Fourth Amendment—that act was considered a search,

which had to be “reasonable” under the circumstances. However, with the advent of intangible

forms of communication, like the telephone or the Internet, it became much more difficult for

judges to determine when certain surveillance practices intruded upon Fourth Amendment rights.

With Katz v. United States, the Court supposedly remedied this by declaring that the Fourth

Amendment protects not only a person’s tangible things, but additionally, his right to privacy.

Katz, however, left unprotected anything a person knowingly exposes to the public. This idea

would form the basis of Smith and Miller. In those cases, the Court held that a customer has no

reasonable expectation of privacy in the phone numbers he dials (Smith) and in checks and

deposit slips he gives to his bank (Miller), as he has exposed them to another and assumed the

risk they could be handed over to the government.

While the third-party doctrine has been criticized by Members of Congress, various

commentators, and others as overly constrictive of Americans’ privacy rights, it appears to fit

relatively well with other Fourth Amendment case law. That being said, advancements in data

collection, automation, and use have some questioning the continued application of this doctrine

in a digital society. Several events have precipitated renewed debates over its continued existence.

First was the Supreme Court’s decision in the GPS tracking case, United States v. Jones, where

two concurring opinions comprising five Justices of the Court called into question various

existing Fourth Amendment theories, including the third-party doctrine, at least with respect to

long-term government monitoring and advanced surveillance technology. Second was the Edward

Snowden leaks relating to the National Security Agency’s telephone metadata program, which has

been primarily justified by Smith and the third-party doctrine. Various Members of Congress have

joined the debate, with some introducing legislation that would require a warrant for access to

records held by third-parties, and others introducing more targeted measures that would limit

access to information such as geolocation data from third-party companies.

With these legal, social, and technological trends in mind, this report explores the third partydoctrine, including its historical background, its legal and practical underpinnings, and its present

and potential future applications. It explores the major third-party doctrine cases and fits them

within the larger Fourth Amendment framework. It surveys the various doctrinal and practical

arguments for and against its continued application. Lastly, this report describes congressional

efforts to supplement legal protection for access to third-party records, as well as suggesting

possible future directions in the law.

Congressional Research Service

The Fourth Amendment Third-Party Doctrine

Contents

Introduction...................................................................................................................................... 1

Fourth Amendment Background ...................................................................................................... 3

Early Definitions of a Fourth Amendment “Search” ................................................................. 4

Reasonable Expectation of Privacy and the Secrecy Model of Privacy .................................... 5

Third-Party Doctrine Jurisprudence................................................................................................. 7

Undercover Informant Cases ..................................................................................................... 7

Miller v. United States—Subpoena for Bank Records............................................................... 9

Smith v. Maryland—Subpoena for Telephone Call Records ................................................... 10

Other Applications of the Third-Party Doctrine ...................................................................... 12

Support for the Third-Party Doctrine............................................................................................. 15

Criticism of the Third-Party Doctrine ............................................................................................ 17

Implications of United States v. Jones on the Third-Party Doctrine .............................................. 20

Congressional Response to the Third-Party Doctrine .................................................................... 23

Conclusion ..................................................................................................................................... 25

Contacts

Author Contact Information........................................................................................................... 26

Congressional Research Service

The Fourth Amendment Third-Party Doctrine

Introduction

In 1967, the Supreme Court pronounced in Katz v. United States that “[w]hat a person knowingly

exposes to the public, even in his own home or office, is not a subject of Fourth Amendment

protection.”1 This rule “that a person has no legitimate expectation of privacy in information he

voluntarily turns over to third parties” is known as the “third-party doctrine.”2 While its reach in

the pre-digital age was relatively limited, the third-party doctrine has provided the government a

powerful investigative tool in a society where people share ever-increasing amounts of

information with others. Many have debated whether these technological and social changes

require the courts to reconsider this doctrine, or, alternatively, whether Congress should step in

and create some form of statutory protection for this information.3

Over the years, the Court has applied the third-party doctrine to two main sets of cases. In one,

the Court has held that people do not have a reasonable expectation that a person with whom they

are communicating will not later reveal that conversation to the police.4 In the second, the Court

extended this doctrine to hold that people are not entitled to Fourth Amendment safeguards for

records given to a third-party or data generated as part of a person’s business transactions with a

third-party. In two of the most prominent third-party cases, Smith v. Maryland and United States v.

Miller, the Court held that government access to telephone calling records and bank records,

respectively, were not Fourth Amendment searches for which warrants were required.5

To be clear, the third-party doctrine does not cover all conceivable information that is transferred

through a third party. For instance, the content of a voice or email communication does not fall

within its scope.6 The courts have reasoned that the service provider is merely the conduit or

intermediary of those communications and not the recipient; thus, the user does not lose privacy

protection in those communications. On the other hand, both non-content and content information

that is shared directly with a service provider is covered by the third-party doctrine (e.g., the

deposit slips or checks shared with a bank and data kept by the bank relating to transactions with

it). Additionally, non-content information derived from private interactions with others is subject

to the third-party doctrine. This covers data such as telephone numbers dialed, email addresses of

those emailed, or websites visited.

1

Katz v. United States, 389 U.S. 347, 351 (1967).

Smith v. Maryland, 442 U.S. 735, 743-44 (1979).

3

See, e.g., Orin Kerr and Greg Nojeim, The Data Question: Should the Third-Party Records Doctrine Be Revisited?,

ABA JOURNAL (Aug. 1, 2012), available at http://www.abajournal.com/magazine/article/

the_data_question_should_the_third-party_records_doctrine_be_revisited/; Orin Kerr, The Case for the Third Party

Doctrine, 107 MICH. L. REV. 561, 575 (2009); Richard A. Epstein, Privacy and the Third Hand: Lessons from the

Common Law of Reasonable Expectations, 24 BERKELEY TECH. L. J. 1199 (2009); Erin Murphy, The Case Against the

Case for Third-Party Doctrine: A Response to Epstein and Kerr, 24 BERKELEY TECH. L. J. 1239 (2009); Stewart Baker,

Smith v. Maryland as a Good First-Order Estimate of Reasonable Privacy Expectations, VOLOKH CONSPIRACY (May 4,

2014), available at http://www.washingtonpost.com/news/volokh-conspiracy/wp/2014/05/04/smith-v-maryland-as-agood-first-order-estimate-of-reasonable-privacy-expectations/.

4

See infra notes 49-66, and accompanying cases.

5

United States v. Miller, 425 U.S. 435 (1976); Smith, 442 U.S. 735.

6

Katz, 389 U.S. at 352 (voice); United States v. Warshak, 631 F.3d 266, 288 (6th Cir. 2010) (email).

2

Congressional Research Service

1

The Fourth Amendment Third-Party Doctrine

The third-party doctrine has been heavily criticized for unnecessarily constricting Americans’

privacy rights.7 But whatever one thinks of the rule that citizens are not entitled to Fourth

Amendment protection when they share information with one another, the third-party doctrine is

largely entrenched in other areas of Fourth Amendment case law. For example, it is not a Fourth

Amendment search for the police to dig through one’s trash left on the curb,8 to track a person’s

movements on public streets,9 and even to surveil a person in a fenced-in backyard with an

aircraft.10 In each of these instances, the Court reasoned that because the person exposed his

activities to the public gaze he was no longer entitled to an expectation of privacy.

In addition to the legal attacks on the third-party doctrine, some have questioned its practical

implications in a society which shares almost every facet of its life with various entities.11 Both

Smith and Miller, decided in the mid- to late-1970s, came before the mass digital revolution

experienced over the last several decades. Since these decisions, there has been a wave of

advancement in data generation, collection, automation, and processing.12 Whether these new

technologies and shifts in social interaction require courts or lawmakers to revise this review is

currently under debate.

Two major events in the past few years typify this ongoing debate. The first is the conversation

prompted by several concurrences in the 2012 GPS tracking case United States v. Jones.13 In two

concurring opinions in that case, five Justices opined that warrantless, pervasive government

location monitoring can violate the Fourth Amendment.14 Commentators have speculated that

these five votes could have significant consequences for other similar ubiquitous surveillance

techniques.15 And at least one member of the Court, Justice Sotomayor, believes that the thirdparty doctrine should be seriously rethought as a whole. The second is the litigation surrounding

the National Security Agency’s telephone metadata program. Several federal courts, including the

Foreign Intelligence Surveillance Court, have applied Smith and the third-party doctrine to uphold

7

See, e.g., United States v. Miller, 425 U.S. 435, 447 (Brennan, J., dissenting); Stephen E. Henderson, The Timely

Demise of the Fourth Amendment Third Party Doctrine, 96 IOWA L. REV. BULL. 396 (2011); CHRISTOPHER SLOBOGIN,

PRIVACY AT RISK: THE NEW GOVERNMENT SURVEILLANCE AND THE FOURTH AMENDMENT 140 (2007).

8

California v. Greenwood, 486 U.S. 35, 43-44 (1988).

9

United States v. Knotts, 460 U.S. 276, 285 (1983).

10

Florida v. Riley, 488 U.S. 445, 451-52 (1989).

11

See DANIEL J. SOLOVE, THE DIGITAL PERSON: TECHNOLOGY AND PRIVACY IN THE INFORMATION AGE 202 (2004) (“The

government’s harvesting of information from the extensive dossiers being assembled with modern computer

technology poses one of the most significant threats to privacy of our time.”).

12

Omer Tene and Jules Polonetsky, Big Data for All: Privacy and User Controls in the Age of Analytics, 11 NW. J.

TECH. & INTELL. PROP. 239, *1(2013) (“Big data is upon us.” Over the past few years, the volume of data collected and

stored by business and government organizations has exploded. The trend is driven by reduced costs of storing

information and moving it around in conjunction with increased capacity to instantly analyze heaps of

unstructured data using modern experimental methods, observational and longitudinal studies, and large scale

simulations. Data are generated from online transactions, email, video, images, clickstream, logs, search queries, health

records, and social networking interactions; gleaned from increasingly pervasive sensors deployed in infrastructure

such as communications networks, electric grids, global positioning satellites, roads and bridges, as well as in homes,

clothing, and mobile phones.”).

13

United States v. Jones, 132 S. Ct. 945 (2012).

14

Id. at 954 (Sotomayor, J., concurring); Id. at 957 (Alito, J., concurring).

15

See, e.g., Priscilla J. Smith, Much Ado About Mosaics: How Original Principles Apply to Evolving Technology in

United States v. Jones, 14 N.C. J.L. & TECH 557, 571 (2013); David Gray & Danielle Keats Citron, A Shattered

Looking Glass: The Pitfalls and Potential of the Mosaic Theory of Fourth Amendment Privacy, 14 N.C. J. L. & Tech.

381 (2013).

Congressional Research Service

2

The Fourth Amendment Third-Party Doctrine

this comprehensive data collection program.16 One district court judge, however, found Smith

outdated and the NSA program too invasive for Smith to still control this legal question.17

With these shifts in technology and legal thinking in mind, this report explores the history and

legal foundations of the third-party doctrine. It will first provide background to the Fourth

Amendment and describe in what instances government investigations trigger its protections. It

will then analyze the Court’s third-party doctrine cases and provide doctrinal and practical

arguments for and against its application. Next, this report will examine how Congress has

responded to the third-party doctrine and whether United States v. Jones and subsequent cases

might alter its future application. Lastly, this report will consider any potential future

developments in this fast-moving area of law.

Fourth Amendment Background

Before the advent of modern communications, government officials could not simply subpoena

an Internet Service Provider (ISP), or Amazon, or Google for information relating to a target of

investigation, but had to enter the suspect’s home or office, sometimes by force, to retrieve

personal information directly themselves.18 During the 18th century, British and colonial officials

conducted searches and seizures of people’s homes with little to no suspicion of wrongdoing

pursuant to either a general warrant, which was used mainly in England, or a writ of assistance,

which was used in the American colonies.19 These indiscriminate government intrusions

contributed to the people’s fear of unrestrained government power and led to the eventual passage

of the Fourth Amendment.

Take, for instance, the formative English search and seizure case Entick v. Carrington, where the

government was investigating John Entick and others for alleged publication of seditious

articles.20 In that case, government officials broke into Entick’s home with “force and arms,”

pried open the locks on his doors, broke open his chests and drawers, and searched his private

papers and books for four hours.21 The officers conducted this search under the guise of a general

warrant, a legal order which states with a high level of generality the places and things to be

searched and seized. In outlawing these practices, Lord Camden of the English bench observed:

16

ACLU v. Clapper, 959 F. Supp. 2d 724 (S.D.N.Y. 2013); Smith v. Obama, No. 2:13-CV-257 (D. Idaho June 3,

2014); In re Application of the Fed. Bureau of Investigation for an Order Requiring the Production of Tangible Things

from [Redacted], No. BR 13-109 (FISA Ct. 2013), available at http://www.uscourts.gov/uscourts/courts/fisc/br13-09primary-order.pdf.

17

Klayman v. Obama, 957 F. Supp. 2d 1, 36 (D.D.C. 2013).

18

Thomas K. Clancy, What is a “Search” Within the Meaning of the Fourth Amendment, 70 ALB. L. REV. 1, 4 (2006)

(“The abhorred English and colonial search and seizure practices involved physical invasions of people’s property.

That was not surprising given that physical invasions were the only way authorities could intrude at the time and given

the lack of technology and other sophisticated surveillance techniques.”); see generally WILLIAM J. CUDDIHY, THE

FOURTH AMENDMENT: ORIGINS AND MEANING 602-1791 (2009).

19

See Thomas K. Clancy, The Role of Individualized Suspicion in Assessing the Reasonableness of Searches and

Seizures, 25 U. MEM. L. REV. 483, 501-512 (1995) (discussing early English and American search and seizure case

law).

20

Entick v. Carrington, 95 Eng. Rep. 807, 807 (C.P. 1765).

21

Id.

Congressional Research Service

3

The Fourth Amendment Third-Party Doctrine

[O]ur law holds the property of every man so sacred, that no man can set his foot upon his

neighbour’s close without his leave; if he does he is a trespasser, though he does no damage

at all; if he will tread upon his neighbour’s ground, he must justify it by law.22

These same intrusive practices also faced disfavor in the American colonies. British officials

often resorted to writs of assistance, a form of general warrant, which permitted house-to-house

searches.23 These legal orders generally failed to allege any illegal activity and were not signed

off on by a judge.24 In the famous Paxton’s Case, leading Boston attorney James Otis attacked

these writs as “the worst instrument of arbitrary power, the most destructive of English liberty,

and the fundamental principles of the constitution, that was ever found in an English law book.”25

John Adams later commented that these indiscriminate intrusions were “the spark in which

originated the American Revolution.”26

To prevent the newly established federal government from committing these incursions into their

lives, the American people ratified the Fourth Amendment as part of the Bill of Rights in 1791. It

reads:

The right of the people to be secure in their persons, houses, papers, and effects, against

unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but

upon probable cause, supported by Oath of affirmation, and particularly describing the place

to be searched, and the person or things to be seized.27

Over the years, the federal courts have struggled to reconcile the first clause of the Amendment,

which requires that all searches and seizures be reasonable, with the second clause, which

requires that all warrants meet certain minimum requirements such as particularly describing the

place to be searched and the things to be seized.28 In any event, the Court must first determine

whether the Fourth Amendment’s restrictions apply at all. This is done by asking whether the

government has conducted a “search,” a legal term of art that cannot be resolved by mere

dictionary definition, but instead requires application of the Supreme Court’s intricate, and at

times contradictory, Fourth Amendment case law.

Early Definitions of a Fourth Amendment “Search”

Although the Fourth Amendment was ratified in 1791, the Supreme Court’s first in-depth

interpretation of what constitutes a Fourth Amendment search did not arise until the 1886 case

United States v. Boyd.29 In Boyd, the government obtained a court order for the Boyds to provide

an invoice of goods they imported which the government planned to use against them in court.

The Boyds produced the invoice, but protested that its production constituted an unreasonable

22

Id. at 817.

Cuddihy, supra note 18, at 380.

24

Id.

25

Brief of James Otis, MASSACHUSETTS SPY, Apr. 29, 1773, at 3.

26

1 JOHN ADAMS & CHARLES FRANCIS ADAMS, THE WORKS OF JOHN ADAMS: SECOND PRESIDENT OF THE UNITED STATES

57 (1856).

27

U.S. CONST. amend. IV.

28

See Scott E. Sundby, A Return to Fourth Amendment Basics: Undoing the Mischief of Camara and Terry, 72 MINN.

L. REV. 383, 383-84 (1988).

29

United States v. Boyd, 116 U.S. 616 (1886).

23

Congressional Research Service

4

The Fourth Amendment Third-Party Doctrine

search and seizure under the Fourth Amendment. Looking to Entick and other pre-Revolutionary

cases for guidance, the Court found that the production of private papers was so similar to an

actual invasion into one’s home that it constituted a Fourth Amendment search.30

Although Boyd instructed that the Fourth Amendment should be “liberally construed,”31 the Court

narrowed the scope of what constitutes a search in Olmstead v. United States.32 In that case,

federal agents investigating the bootlegging activities of a criminal syndicate placed a wiretap on

several phone lines running from the homes and office of four suspects. At no point did the

officers trespass upon the defendants’ property to conduct the tap. The Court held that these

wiretaps should not be considered a search as the “Amendment itself shows that the search is to

be of material things—the person, house, papers, and effects,” and the intangible voice of the

defendants was not covered by its literal terms. The Court further found that the agents did not

engage in “an actual physical invasion” of Olmstead’s home for purposes of conducting the

wiretap.33 Dissenting in Olmstead, Justice Brandeis observed that in the past, most notably in

Boyd, the Court “refused to place an unduly literal construction” upon the Fourth Amendment.34

Instead, he continued:

The protection guaranteed by the amendment[] is much broader in scope. The makers of our

Constitution ... sought to protect Americans in their beliefs, their thoughts, their emotions

and their sensations. They conferred, as against the government, the right to be let alone-the

most comprehensive of rights and the right most valued by civilized men. To protect, that

right, every unjustifiable intrusion by the government upon the privacy of the individual,

whatever the means employed, must be deemed a violation of the Fourth Amendment.35

Nonetheless, in the ensuing years, the Court assessed whether there was a search based on

whether a physical trespass occurred. For instance, it was not considered a search when police

engaged in eavesdropping absent a trespass.36 However, where the police trespassed upon the

suspect’s property—even by an inch—the Court held that the Fourth Amendment applied.37 Forty

years later the Court would expressly overrule Olmstead’s literal, trespass-based interpretation of

the Fourth Amendment for a privacy-based test.

Reasonable Expectation of Privacy and the Secrecy Model of

Privacy

In 1967, the Court decided Katz v. United States, which abandoned the literal interpretation of the

Fourth Amendment—one that protected only persons, houses, papers, and effects—to one that

also protected intangible interests such as privacy.38 However, while the Court sought to expand

what the Fourth Amendment protects, certain passages in Katz simultaneously foreclosed

30

Id.

Id.

32

Olmstead v. United States, 277 U.S. 438 (1928).

33

Id. at 466.

34

Id. at 476 (Brandeis, J, dissenting).

35

Id. at 478 (Brandeis, J, dissenting).

36

Goldman v. United States, 316 U.S. 129, 135 (1942).

37

Silverman v. United States, 365 U.S. 505, 511-12 (1961).

38

Katz v. United States, 389 U.S. 347 (1967).

31

Congressional Research Service

5

The Fourth Amendment Third-Party Doctrine

protection for anything a person exposes to the public or another person. This would have

significant consequences for government access to records and other information held by third

parties.

In Katz, the FBI was investigating the illegal gambling activities of Mr. Katz. The FBI had

attached an electronic eavesdropping device to the outside of the telephone booth in which Katz

made calls and offered evidence of these calls against Katz at his prosecution. Quite sensibly, the

parties framed the question presented in light of Olmstead’s physical trespass theory, the

controlling Fourth Amendment theory of the day. They debated whether a telephone booth was a

“constitutionally protected area” such that attaching the listening device to its outside would

constitute a Fourth Amendment search.39 The Court, speaking through Justice Stewart, looked

beyond this traditional inquiry into protected areas, and instead declared that the “Fourth

Amendment protects people, not places.”40 He observed that the “Amendment protects individual

privacy against certain kinds of governmental intrusion,” but also instructed that it “cannot be

translated into a general constitutional ‘right to privacy[.]’” Such a “right to be let alone by other

people” is left largely to protection under state law.41 In bypassing Olmstead and formulating the

scope of the Fourth Amendment in light of privacy principles, it became necessary for the Court

to lay down a rule to determine which privacy interests would be protected and which would not.

Unfortunately, the majority provided little by way of guidance on the scope of this rule, beyond to

say that what a person “seeks to preserve as private, even in an area accessible to the public, may

be constitutionally protected” and that the use of the electronic eavesdropping device violated

Katz’s privacy, upon which he “justifiably relied.”42 Concurring, Justice Harlan developed a twopart framework for answering this question, which would become Katz’s controlling test.43 Under

Justice Harlan’s formulation, a court first asks whether the person exhibited an actual or

subjective expectation of privacy and second whether society is likely to deem that expectation

reasonable.44

Beyond its general assertion that the Fourth Amendment protects people, not places, the majority

made an equally far-reaching observation that “[w]hat a person knowingly exposes to the public,

even in his own home or office, is not a subject of Fourth Amendment protection.”45 This rule

adopts what can be called the secrecy model of privacy. Under the secrecy model, once a fact is

disclosed to the public in any way, the information is no longer entitled to privacy protection.46

This secrecy model, along with the assumption of the risk theory discussed below, would form

the underpinnings of the modern third-party doctrine.

39

Id. at 349.

Id. at 351.

41

Id. at 350.

42

Id. at 351, 353.

43

Id. at 360 (Harlan, J., concurring); see Kyllo v. United States, 533 U.S. 27, 32-33 (2001) (“In assessing when a

search is not a search, we have applied somewhat in reverse the principle first enunciated in Katz v. United States. ... As

Justice Harlan’s oft-quoted concurrence described it, a Fourth Amendment search occurs when the government violates

a subjective expectation of privacy that society recognizes as reasonable.”).

44

Id. at 361 (Harlan, J. concurring).

45

Katz, 389 U.S. at 351-52.

46

Solove, supra note 11, at 8.

40

Congressional Research Service

6

The Fourth Amendment Third-Party Doctrine

Third-Party Doctrine Jurisprudence

The idea that what a person knowingly exposes to the public is not entitled to constitutional

protection was not an invention of the Katz court, but was embedded in Fourth Amendment

jurisprudence for quite some time. In one of the first Fourth Amendment cases, Ex parte Jackson,

the Court held that anything “exposed” on the outside of a parcel of mail is not entitled to Fourth

Amendment protection.47 Similarly, under what has come to be known as the “plain view”

doctrine, Justice Brandeis noted in the 1927 case United States v. Lee that the use of a searchlight

to view cases of liquor on the deck of a ship was not a Fourth Amendment search.48 More

prominently, the Court decided a series of cases throughout the 20th century holding that people

do not have a reasonable expectation that a person with whom they are conversing will not later

reveal that conversation to the police. The third-party doctrine would later be extended to

documents and transactional data shared with third parties.

Undercover Informant Cases

In a series of five cases throughout the 20th century, the Supreme Court assessed the

constitutionality of the use of undercover agents or informants under the Fourth Amendment. In

On Lee v. United States, the government wired an “undercover agent” with a microphone and sent

him into On Lee’s laundromat to engage him in incriminating conversation.49 An agent of the

Bureau of Narcotics sat outside with a receiving set to hear the conversation. In the course of

these conversations, On Lee made incriminating statements, which the agent later testified to at

On Lee’s trial. On Lee argued that this evidence was obtained in violation of the Fourth

Amendment. In an opinion authored by Justice Jackson, the Court disagreed, noting that On Lee

was “talking confidentially and indiscreetly with one he trusted” and that the agent was let into

his shop “with the consent, if not implied invitation” of On Lee.50

In a similar case, Lopez v. United States, the defendant attempted to bribe an internal revenue

agent, who during some of these conversations was wearing a recording device.51 At trial, Lopez

moved to suppress evidence of the wire recordings as fruits of an unlawful search. Relying on the

On Lee decision, the Court rejected this argument on the grounds that the defendant consented to

the agent being in his office and “knew full well” that the statements he made to the agent could

be used against him.52 Further, the Court noted that the listening device was not used to intercept

conversations the agent could not have otherwise heard, but “instead, the device was used only to

obtain the most reliable evidence possible of a conversation in which the Government’s own

agent was a participant and which that agent was fully entitled to disclose.”53

47

Ex parte Jackson, 96 U.S. 727, 736 (1877).

See United States v. Lee, 274 U.S. 559 (1927); see also United States v. Martin, 806 F.2d 204, 207 (8th Cir. 1986)

(“[I]t was inappropriate to subject the agent’s conduct of looking through the window of the truck to Fourth

Amendment scrutiny in the first place. The agent’s mere observation of gun parts left in plain view on the front seat of

the truck did not implicate any Fourth Amendment rights.”).

49

On Lee v. United States, 343 U.S. 747, 748 (1952).

50

Id. at 751-52.

51

Lopez v. United States, 373 U.S. 427, 430 (1963).

52

Id. at 437.

53

Id. at 439.

48

Congressional Research Service

7

The Fourth Amendment Third-Party Doctrine

In Lewis v. United States, the government sent an undercover federal narcotics agent to the

defendant’s home several times to purchase marijuana.54 Over the defendant’s objections, the

agent was permitted to recount the conversations at trial. Upon review, the Supreme Court held

that the conversations were not protected under the Fourth Amendment as the defendant had

invited the federal agent into his home and that the statements were “willingly” made to the

agent.55

Finally, in Hoffa v. United States, a government informant relayed to federal law enforcement

agents the many conversations he had with Jimmy Hoffa about Hoffa’s attempt to tamper with a

jury.56 Because the informant did not enter Hoffa’s hotel room by force, was invited to participate

in the conversations by Hoffa, and was not a “surreptitious eavesdropper,” the Court concluded

that the Fourth Amendment had not been violated.57

There appear to be two motivating principles underlying these undercover informant cases. In one

sense, the Court was applying Olmstead’s physical invasion test: because the informants had not

trespassed into the defendants’ homes or offices—in the words of pre-Katz case law, their

“constitutionally protected areas”—there could be no constitutional invasion.58 Rather, in each

instance, the informant was invited onto the premises. For example, in On Lee, the Court

observed that On Lee could not raise the issue of trespass as he had consented, if not invited, the

agent to enter his business. A claim of trespass could only be made if the agent had entered by

force or by show of authority.59 In another sense, the Court found that voluntarily telling another

person something gave him consent to share that information with another person including the

government.60 For instance, Hoffa instructed that the Fourth Amendment does not protect “a

wrongdoer’s misplaced belief that a person to whom he voluntarily confides his wrongdoing will

not reveal it.”61

Note that these cases came before Katz shifted the Fourth Amendment focus from property to

privacy. Whether Katz would disturb this line of cases was a matter of “considerable

speculation”62 until the Court decided United States v. White four years later. In White, an

undercover informant wearing a radio transmitter engaged the defendant in several incriminating

conversations, four of which took place at the informant’s house, and several other conversations

took place in the defendant’s home, a restaurant, and in the informant’s car.63 The court of appeals

in White interpreted Katz as implicitly overruling this line of cases as it was based on a trespass

54

Lewis v. United States, 385 U.S. 206 (1966).

Id at 210, 212.

56

Hoffa v. United States, 385 U.S. 293, 296 (1966).

57

Id. at 302.

58

See Lopez, 373 U.S. at 439 (“And the device was not planted by means of an unlawful physical invasion of

petitioner’s premises under circumstances that would violate the Fourth Amendment.”).

59

See On Lee, 343 U.S. at 751-52.

60

Hoffa, 385 U.S. at 302 (“[The government agent] was in the suite by invitation, and every conversation which he

heard was either directed to him or knowingly carried on in his presence.”); Lopez, 373 U.S. at 438 (“The only

evidence obtained consisted of statements made by the [defendant] to the [government agent], statements which [the

defendant] knew full well could be used against him by [the government agent] if he wished.”).

61

Hoffa, 385 U.S. at 302.

62

See 1 WAYNE R. LAFAVE, SEARCH AND SEIZURE § 2.2(f) (2004).

63

United States v. White, 401 U.S. 745, 746-47 (1971).

55

Congressional Research Service

8

The Fourth Amendment Third-Party Doctrine

doctrine that was “squarely discarded” in Katz.64 The Supreme Court disagreed, however, and

upheld the surreptitious surveillance. The opinion accepted that the trespass rationale could not

survive after Katz, but that the undercover informant cases were also supported by a “second and

independent ground”—that the informant was not an uninvited eavesdropper, but a party to the

conversation who was free to report what he heard to the authorities.65 For the Court, White had

assumed the risk that information he shared with the informant could be shared with the police.66

With White, the Court combined several ideas in its Fourth Amendment jurisprudence: first, that

it is unreasonable for people to expect privacy in information they share with another, and second,

that they assume the risk that that information can be handed over to the government.67 With these

two theories in mind, the Court resolved two major third-party doctrine cases in the 1970s, United

States v. Miller and Smith v. Maryland.68 These cases would become the cornerstone of the

modern third-party doctrine, and have been heavily relied upon by government officials to access

various types of transactional data without a search warrant.

Miller v. United States—Subpoena for Bank Records

In 1976, the Court took up its first major third-party doctrine case to deal with transactional

documents in Miller v. United States. In that case, agents of the Treasury Department’s Alcohol,

Tobacco, and Firearms Bureau were investigating Mitch Miller for his participation in an illegal

whiskey distillery.69 The agents subpoenaed the presidents of several banks in which Miller had

an account to produce all records of accounts including savings, checking accounts, and any loans

he may have had. The banks never informed Miller that the subpoenas had been served, but

ordered their employees to comply with the subpoenas. At one bank, an agent was shown

microfilm of Miller’s account and provided copies of “one deposit slip and one or two checks.”70

At the other bank, the agent was shown similar records and was given copies of “all checks,

deposit slips, two financial statements, and three monthly statements.”71 Copies of the checks

were later introduced into evidence at Miller’s trial.

64

United States v. White, 405 F.2d 838 (7th Cir. 1969).

White, 401 U.S. at 750 (quoting On Lee, 343 U.S. at 753-54) (“It would be a dubious service to the genuine liberties

protected by the Fourth Amendment to make them bedfellows with spurious liberties improvised by farfetched

analogies which would liken eavesdropping on a conversation, with the connivance of one of the parties, to an

unreasonable search or seizure.”)).

66

Id. at 752 (“Inescapably, one contemplating illegal activities must realize that his companions may be reporting to the

police.”). Assumption of the risk is more commonly found in the context of tort law, where a person assumes certain

risks that accompany the activities he is engaged in. See Murphy v. Steeplechase Amusements Co., 250 N.Y. 479

(1929) (Cardozo, J.) (“Volenti non fit injuria. One who takes part in such a sport accepts the dangers that inhere in it so

far as they are obvious and necessary, just as a fencer accepts the risk of a thrust by his antagonist or a spectator at a

ball game the chance of contact with the ball.”).

67

While primarily concerned with the Fifth Amendment right to self-incrimination, Couch v. United States , 409 U.S.

322, 335(1973), observed that “there can be little expectation of privacy where [tax] records are handed to an

accountant, knowing that mandatory disclosure of much of the information therein is required in an income tax

return.”).

68

United States v. Miller, 425 U.S. 435 (1976); Smith v. Maryland, 442 U.S. 735 (1979).

69

Miller, 425 U.S. at 437.

70

Id. at 438.

71

Id.

65

Congressional Research Service

9

The Fourth Amendment Third-Party Doctrine

The lower court held that the government had unlawfully circumvented the Fourth Amendment

by first requiring the banks to maintain the customer’s records for a certain period of time and

second by using insufficient legal process to obtain those records from the bank. In a 7-2 ruling,

the Supreme Court reversed and held that subpoenaing the bank records without a warrant did not

violate the Fourth Amendment. The opinion by Justice Powell discarded the first argument by

noting that previous case law held that merely requiring the bank to retain its customers’ records

did not constitute a Fourth Amendment search.72 That previous case, however, did not resolve

whether a subpoena was sufficient to access those documents.73 Miller argued that the bank kept

copies of personal records that he gave to the bank for a limited purpose and in which he retained

a reasonable expectation of privacy under Katz. The Court, applying language from Katz, noted

that “[w]hat a person knowingly exposes to the public ... is not a subject of Fourth Amendment

protection.”74 The Court concluded that banking documents were not “confidential

communications,” but rather negotiable instruments that were required to transact business

between the customer and the bank. All of the documents contained information “voluntarily

conveyed to the banks and exposed to their employees in the ordinary course of business.”75 As

with the undercover agent cases, once documents were shared with the bank, they could then be

given to the government without requiring a search warrant. Citing to White, Justice Powell

instructed that a bank customer “takes the risk, in revealing his affairs to another, that the

information will be conveyed by that person to the government.”76 Looking to both this

assumption of the risk theory and the secrecy model, the Court then included the following

sentence which would come to encapsulate the third-party doctrine:

This Court has held repeatedly that the Fourth Amendment does not prohibit the obtaining of

information revealed to a third party and conveyed by him to Government authorities, even if

the information is revealed on the assumption that it will be used only for a limited purpose

and the confidence placed in the third party will not be betrayed.77

Based on this assertion, Miller could have no reasonable expectation of privacy in the bank

records and thus the introduction of them at his prosecution did not contravene the Fourth

Amendment.

Smith v. Maryland—Subpoena for Telephone Call Records

Several years later, the Court took up the second major third-party doctrine case, Smith v.

Maryland,78 which would have major implications for government collection of transactional

records, especially those held by third-party companies.

In Smith, the police were investigating the robbery of a young woman, who gave the police a

description of her assailant and the vehicle seen near the scene of the crime.79 The police later

72

Miller, 425 U.S. at 441 (quoting California Bankers Assn. v. Shultz, 416 U.S. 21, 54 (1974)).

See California Bankers Ass’n, 416 U.S. at 54 n.24.

74

Miller, 425 U.S. at 442 (quoting Katz v. United States, 389 U.S. 347, 351 (1967)).

75

Id.

76

Id. at 443.

77

Id. at 443.

78

Smith v. Maryland, 442 U.S. 735 (1979).

79

Id. at 737.

73

Congressional Research Service

10

The Fourth Amendment Third-Party Doctrine

spotted a man matching the victim’s description driving an identical vehicle in her neighborhood,

which they traced back to Michael Smith. Upon police request, the telephone company installed a

pen register at its central office to record the telephone numbers dialed from Smith’s home. The

device was installed without a warrant or court order. Through the pen register, the police learned

that a call was placed from Smith’s home to the victim’s phone, which would eventually connect

Smith to the robbery. At trial, Smith claimed that any evidence obtained from the pen register

violated his Fourth Amendment rights as the police failed to obtain a warrant before installing it.

This motion was denied, Smith was later convicted of robbery, and the appeals court affirmed his

conviction, holding that the installation of the pen register was not a Fourth Amendment search.80

In line with Justice Harlan’s formulation of the Katz privacy test, the Supreme Court asked the

following questions: first, whether Smith had a subjective expectation of privacy in the numbers

he dialed, and second, whether that expectation was reasonable.81 As to the former, the Court

“doubt[ed] that people in general entertain any actual expectation of privacy in the numbers they

dial.”82 The Court assumed that people, in the main, know and understand that they must convey

the dialed numbers to the company to complete the call; that the company has a process of

recording those numbers; and that the company actually does record those numbers for various

business reasons. It deduced this partially from the fact that phone books inform consumers that

the telephone companies “can frequently help in identifying to authorities the origin of

unwelcome and untroublesome calls” and that customers see a list of their calls recorded on their

monthly phone bills.83

Even if Smith did harbor a subjective expectation of privacy, the Court found that “this

expectation is not ‘one society is prepared to recognize as ‘reasonable.’”84 Justice Blackmun cited

to Miller, White, Hoffa, and Lopez for the proposition that “a person has no legitimate expectation

of privacy in information that he voluntarily turns over to third parties.”85 Because Smith

“voluntarily conveyed” the telephone numbers to the company in the process of making the call,

he had “exposed” that information to the company’s equipment in the “ordinary course of

business” and thus could not reasonably expect privacy in that information.86 Moreover, the Court

found that Smith “assumed the risk” that the telephone company would reveal to the police the

numbers he dialed.87

Although Smith was the Court’s last significant pronouncement on the parameters of the thirdparty doctrine, the lower federal courts have applied it in various contexts, with a significant

number of these cases dealing with the transfer of electronic information.

80

Smith v. Maryland, 283 Md. 156, 173 (1978).

Smith, 442 U.S. at 740.

82

Id. at 742.

83

Id. at 742-43

84

Id. at 743 (quoting Katz, 389 U.S. at 361).

85

Id. at 743-44.

86

Id. at 744.

87

Id.

81

Congressional Research Service

11

The Fourth Amendment Third-Party Doctrine

Other Applications of the Third-Party Doctrine

After Miller and Smith, the courts have applied the third-party doctrine to a host of various

scenarios including metadata connected to Internet communications, cell phone location

information, and utility billing records, among others. These cases generally divide along a

content/non-content distinction: the content of a communication, such as the body of an email,

does not fall within third-party doctrine, and other Fourth Amendment rules apply. Addressing

information, such as the to/from line in an email, the outside of a letter, or the telephone numbers

dialed, however, are covered by the doctrine. There have been various rationales for this divide,

the most compelling being the difference between the recipient of the information and companies

that act merely as a conduit or intermediary between two people communicating with each other.

The difference in constitutional treatment between the content of a communication and its noncontent addressing information dates at least as far back as the 19th century. In the 1877 case Ex

parte Jackson, the Supreme Court held that the content of a mailed letter was protected under the

Fourth Amendment, while the information exposed to the public, such as the address written on

the outside, was not.88 This dichotomy was further developed in Katz and Smith. In Katz, the

Court protected the content of Mr. Katz’s communication (his voice), noting that a caller is

“surely entitled to assume that the words he utters into the mouthpiece will not be broadcast to the

world.”89 Non-content information was not before the Court in Katz. On the other hand, Smith left

non-content information, the numbers he dialed, unprotected, as pen registers do not allow law

enforcement to “hear sound” and “[n]either the purport of any communication between the caller

and the recipient of the call, their identities, nor whether the call was even completed is

disclosed[.]”90

This distinction between content and non-content has also been applied in the lower courts. In

United States v. Warshak, the Sixth Circuit Court of Appeals held that individuals enjoy a

reasonable expectation of privacy in the content of their emails.91 The panel noted that “email

requires strong protection under the Fourth Amendment; otherwise, the Fourth Amendment would

prove an ineffective guardian of private communication, an essential purpose it has long been

recognized to serve.”92 Following Smith’s lead, the courts have taken the opposite approach to

non-content or addressing information that accompanies an email or other electronic

communications. In United States v. Forrester, for example, the Ninth Circuit Court of Appeals

held that the to/from addresses of emails, the IP addresses of websites a person visits, and the

total volume of data transmitted to or from a certain account were not subject to Fourth

Amendment protection.93 The Ninth Circuit found that like the telephone numbers in Smith, email

and Internet users should know that addressing information “is provided to and used by Internet

Service Providers (ISP) for the specific purpose of directing the routing of information.”94

88

Ex parte Jackson, 96 U.S. 727, 733 (1877); see also United States v. Jacobsen, 466 U.S. 109, 114 (1984) (“Letters

and other sealed packages are in the general class of effects in which the public at large has a legitimate expectation of

privacy; warrantless searches of such effects are presumptively unreasonable”).

89

Katz v. United States, 389 U.S. 347, 352 (1967).

90

Smith, 442 U.S. at 741 (quoting United States v. New York Tel. Co. 434 U.S. 159, 167 (1977)).

91

United States v. Warshak, 631 F.3d 266, 288 (6th Cir. 2010); see also City of Ontario v. Quon, 560 U.S. 746, 757

(2010) (assuming that petitioner had reasonable expectation of privacy in content of emails).

92

Id. at 286.

93

United States v. Forrester, 512 F.3d 500, 510 (9th Cir. 2007).

94

Id. at 510.

Congressional Research Service

12

The Fourth Amendment Third-Party Doctrine

Moreover, the court noted that although the government can make an “educated guess” about

what was said in a message or viewed on a particular website, this information does not

“necessarily reveal any more about the underlying contents of the communication than do phone

numbers.”95 Further emphasizing this distinction, while Smith covered the telephone numbers a

person dials to make a call, government access to the numbers dialed after a call has been placed,

known as “post-cut through dialed digits,” is considered a Fourth Amendment search.96 These

numbers, which might include “bank account numbers, Social Security numbers, prescription

numbers, and the like,” constitute the “contents of communications” and are “the kind of

information that an individual wants and reasonably expects to be kept private.”97

Another dividing line between protected and unprotected information pertains to the identity of

the service provider in the chain of communication. If the provider is seen as a party to the

transaction and is a recipient of the information, the records are generally considered “business

records” of that company and subject to the third-party doctrine. This rationale is similar to that

applied in the undercover informant cases. Although the information provided to an informant

constitutes the content of the communication, it is not protected because it was spoken directly to

the agent—in other words, the agent was the recipient of that information. Alternatively, where

the company merely acts as a conduit or intermediary and “passively convey[s]” that information

to an end-user, the material is generally not subject to the third-party doctrine.98

In Warshak, the Sixth Circuit noted that the ISP was acting as an “intermediary that makes email

communication possible.”99 Just like the post office which acts as an intermediary of a letter, and

the telephone company which acts as an intermediary to the voice content of phone calls, “emails

must pass through an ISP’s server to reach their intended recipient.”100 And just as the police are

prohibited from accessing communications from the post office or a telephone company without

first obtaining a warrant, the Sixth Circuit held that a warrant should equally be required to access

more modern forms of communications.101 Distinguishing the bank records case Miller, the court

found that whereas the bank records, checks, and deposit slips in Miller were given directly to the

banks to be used in the “ordinary course of business,” the ISP was the “intermediary, not the

intended recipient of the emails.”102 The court rejected the government’s arguments that the

“ability” and “right” of the ISP to access emails stored on its servers should eliminate any Fourth

Amendment privacy interests, as a similar ability of the telephone operators in Katz to listen in on

conversations carried over their system did not eliminate a user’s reasonable expectation of

privacy.103

95

Id.

See In Re of Applications of the United States of America for Orders (1) Authorizing the Use of Pen Registers and

Trap and Trace Devices and (2) Authorizing Release of Subscriber Information, 515 F. Supp. 2d 325, 339 (E.D.N.Y.

2007); see also In re Application of the United States of America for an Order Authorizing (1) Installation and Use of a

Pen Register and Trap and Trace Device or Process, (2) Access to Customer Records, and (3) Cell Phone Tracking, 441

F. Supp. 2d 816, (S.D. Tex. 2006) (deciding case on statutory grounds but noting constitutional concern with access to

post-cut-through dialed digits without a warrant based upon probable cause).

97

In re Application for Subscriber Information, 515 F. Supp. 2d at 336.

98

Forrester, 512 F.3d at 510.

99

Warshak, 631 F.3d at 286.

100

Id.

101

Id.

102

Id. at 288.

103

Id. (emphasis in original).

96

Congressional Research Service

13

The Fourth Amendment Third-Party Doctrine

Another prominent example of this conduit versus recipient dichotomy can be found in lower

federal court cases treating cell location data as a business record not subject to Fourth

Amendment protection. In a 2013 Fifth Circuit Court of Appeals case, the government sought

access to two months of historical cell site location data, which provides the location of a cell

phone based on its proximity to the nearest cell tower.104 Noting this distinction between

intermediary and recipient, the court found that cell site records are “clearly business records” for

which the third-party doctrine should apply, as the cell provider is a party to the transaction; the

location information is not transferred to anyone but the provider; and the location information is

needed to route the call.105 Like the Fifth Circuit, several lower courts have applied the third-party

doctrine to hold that access to cell site location information is not a Fourth Amendment search.106

However, over the past several years, a growing number of judges have pushed back against

government attempts to circumvent the Fourth Amendment warrant requirement when seeking

information about an individual’s cell phone location data. The District Court for the Eastern

District of New York, for instance, found that while the third-party doctrine generally covers the

type of location information produced by a cell phone call, the “cumulative” collection of 113

days of constant surveillance implicated sufficiently heightened privacy interests to warrant an

exception to the third-party doctrine.107 This argument is based on the “mosaic theory” of the

Fourth Amendment, which holds that while short-term monitoring may not reveal anything overly

private about an individual, the aggregation of this information can be much more revealing.108 In

an alternative approach, the Third Circuit Court of Appeals reasoned that a cell phone user does

not “voluntarily” share his location with a cell phone provider “in any meaningful way,”

prohibiting application of the third-party doctrine, but held that it was left to the discretion of the

magistrate judge whether a warrant would be required.109

A more recent legal problem facing the lower courts is determining whether the third-party

doctrine should apply to “cell tower dumps.” These are instances in which the government is

looking for the cell phone records of unknown persons who may have made a cell phone call after

a reported crime, say, a bank robbery. The government requests all the calls made from the

nearest cell tower within a certain period of time.110 The few courts that have addressed the issue

have split on whether a warrant is required.111 Thus far, the reasoning in these cases has not been

fully developed.

104

In re Application of the United States of America for Historical Cell Site Data, 724 F.3d 600, 602 (5th Cir. 2013).

Id. at 612.

106

See, e.g., In re Application of the United States of America for an Order for Disclosure of Telecommunications

Records and Authorizing the Use of a Pen Register and Trap and Trace, 405 F. Supp. 2d 435, 449-50 (S.D.N.Y. 2005);

United States v. Graham, 846 F. Supp. 2d 384, 403 (D. Mar. 2012); United States v. Benford, No. 2:09-CR-86, 2010

WL 1266507 (N.D. Ind. 2010).

107

In re Application of the United States of America for an Order Authorizing the Release of Historical Cell-Site

Information, 809 F. Supp. 2d 113, 126 (E.D.N.Y. 2011).

108

See infra “Implications of United States v. Jones on the Third-Party Doctrine,” pp. 21-23.

109

See In re Application of the United States of America for an Order Directing a Provider of Electronic

Communication Service to Disclose Records to the Government, 620 F.3d 304, 317-18 (3d 2010).

110

See Brian L. Owsley, The Fourth Amendment Implications of the Government’s Use of Cell Tower Dumps in Its

Electronic Surveillance, 16 U. PA. J. CONST. L. 1, 1-2 (2013).

111

Compare In re Application of the United States of America for an Order Pursuant to 18 U.S.C. § 2703(d), 964 F.

Supp. 2d 674, 678 (denying access to cell tower dump records) with United States v. Capito, No. 3:10-CR-8050 (D.

Ariz Sept 14, 2011) (upholding access to cell tower dump records).

105

Congressional Research Service

14

The Fourth Amendment Third-Party Doctrine

Beyond the specific factors the courts have used to determine whether the third-party doctrine

should apply (e.g., content versus non-content, intermediary versus recipient), there have been

both doctrinal and practical arguments made for and against its very existence.

Support for the Third-Party Doctrine

Perhaps the strongest argument in support of the third-party doctrine is its ability to be

harmonized with the rest of Fourth Amendment case law. One only has to quickly scan the

Supreme Court Reporter to realize that the third-party doctrine is consistent with numerous other

cases which hold that acts or things revealed to the public are not entitled to Fourth Amendment

protection.

Take, for instance, the garbage collection case, California v. Greenwood.112 There, the police

requested that a trash collector pick up a suspect’s plastic trash bags left in front of his house so

the officer could search it for contraband or other evidence of criminal activity. The Court

concluded that the defendant was not entitled to a reasonable expectation of privacy in his trash as

he discarded it where it could be accessed by the public.113 Similarly, in United States v. Knotts,

the Court held that a person does not have a legitimate privacy expectation in his public

movements as he voluntarily conveys this information to anyone who wants to look.114 This

theory has also been applied to cases where police flew an airplane 1,000 feet and a helicopter

400 feet over private property in search of illegal activity.115 The rationale in those cases was that

any member of the public flying in federally regulated airspace could have looked down and seen

what the officers saw, vitiating any privacy expectation in that space.116 In United States v.

Jacobsen, the Court held that it was not a search when police opened a mailed package after its

contents had already been viewed by an employee of a private freight carrier.117 There, the Court

observed that once the defendant’s privacy expectation had been frustrated by one person, it

became public information subject to government investigation.118

As a more practical matter, assistance from third parties is utilized by law enforcement in almost

every investigation. When investigating a murder, robbery, or any other crime committed in the

real world, police officers will usually interview witnesses to obtain facts about the crime. To

conduct these interviews, the officers generally need not obtain a warrant, and witnesses who

refuse to cooperate can be compelled to testify with a grand jury subpoena.119 It could be argued

112

California v. Greenwood, 486 U.S. 35, 37 (1988).

Id. at 42.

114

United States v. Knotts, 460 U.S. 276, 281-82 (1983).

115

California v. Ciraolo, 476 U.S. 207, 213-14 (1986) (airplane); Florida v. Riley, 488 U.S. 445, 455 (1989)

(helicopter).

116

Ciraolo, 476 U.S. at 213-214; Riley, 488 U.S. at 451.

117

United States v. Jacobsen, 466 U.S. 109, 117-18 (1984).

118

Id. at 117. Like the Fourth Amendment, under the privacy tort of intrusion upon seclusion, which subjects one to

liability for intruding upon the solitude or seclusion of another, there is no liability for observing or taking a person’s

photograph in public for his appearance is “open to the public eye.” RESTATEMENT (SECOND) OF TORTS § 652B cmt. b

(2013).

119

United States v. Dionisio, 410 U.S. 1, 9-10 (1973) (observing the “historically grounded obligation of every person

to appear and give his evidence before the grand jury. ‘The personal sacrifice involved is a part of the necessary

contribution of the individual to the welfare of the public.’ And while the duty may be ‘onerous’ at times, it is

‘necessary to the administration of justice.’”).

113

Congressional Research Service

15

The Fourth Amendment Third-Party Doctrine

that this process of fact finding is very similar to requesting documentary evidence held by third

parties and the same standard should be applied to each.

In this same vein, Professor Orin Kerr has defended the third-party doctrine on the ground that it

maintains the appropriate balance of privacy and security in the face of technological change.120

Without the ability to use third parties such as telephone or Internet companies, Kerr posits, the

criminal would traditionally have to go out into the public to commit his crime where the Fourth

Amendment offers more limited protection. He argues that a criminal can use the services of

these third parties to commit crimes without having to expose these activities to areas open to

public surveillance.121 This, he posits, upsets the privacy-security balance that undergirds the

Fourth Amendment because it would require police to have probable cause to obtain any evidence

of the crime: “The effect would be a Catch-22: The police would need probable cause to observe

evidence of the crime, but they would need to observe evidence of the crime first to get probable

cause.”122 Kerr contends that the third-party doctrine responds to this imbalance by providing the

same amount of protection regardless of whether the defendant commits the crime on his own or

through the use of a third-party service.

From an institutional perspective, one might argue that the courts are not the proper branch of the

federal government to resolve privacy disputes related to information handed over to thirdparties. Once the Supreme Court outlaws, or significantly limits, a certain police practice, it

“constitutionalizes” it, and only the Court or a constitutional amendment could overturn this

decision. Instead, some argue that when creating rules that pertain to new technologies, Congress,

and legislatures generally, might be best fitted to find the appropriate balance between privacy

and security, while providing the necessary flexibility to change this rule as technology

changes.123

Another argument in support of the third-party doctrine is that the companies which hold a

person’s records “own” them, as they are in possession of them and are generally the ones that

create them.124 Once possessed by the company, the argument runs, it can transfer these

documents to others free from the permission of the subject of the documents. The Court relied

on this theory in Miller, where it noted that the bank records were not the defendant’s “private

papers,” and as such he could “assert neither ownership nor possession.”125 Instead, they were

deemed “the business records of the banks.”126 This argument is buttressed by the theory that the

First Amendment protects a person’s right to communicate facts to others.127

120

See Orin Kerr, The Case for the Third Party Doctrine, 107 MICH. L. REV. 561, 575 (2009).

Id.

122

Id. at 576.

123

See Orin Kerr, The Fourth Amendment and New Technologies: Constitutional Myths and the Case for Caution, 102

MICH. L. REV. 801, 859 (2004).

124

Slobogin, supra note 7, at 157 (describing arguments for and against the possessory interest argument).

125

United States v. Miller, 425 U.S. 435, 440-41 (1976)

126

Id.

127

See Eugene Volokh, Freedom of Speech and Information Privacy: The Troubling Implications of a Right to Stop

People from Speaking About You, 52 STAN. L. REV. 1049, 1053 (2000).

121

Congressional Research Service

16

The Fourth Amendment Third-Party Doctrine

Criticism of the Third-Party Doctrine

While the third-party doctrine appears to fit reasonably well with the rest of Fourth Amendment

case law, and has other weighty arguments in its favor, it has also had its share of vocal critics

both on and off the Court. There have been four major arguments against its application: (1)

privacy is not an all-or-nothing proposition that is lost once information is disclosed to another

person or company; (2) information sent to third-party companies is not actually “voluntary,” as

people need these services to participate in modern society; (3) the judiciary should not impose

privacy regimes on the citizenry without engaging in a more comprehensive privacy analysis; and

(4) failing to protect information shared with others has the potential to breed distrust among

people or businesses communicating with each other.

The first major argument against the third-party doctrine challenges the notion that once privacy

is lost to one person, it is lost to the world. At bottom, this is a challenge to the secrecy model of

the Fourth Amendment. The secrecy theory of privacy has been criticized for not taking into

consideration that people may not want to engage in “total disclosure” of information they share

with others, but instead seek to selectively disclose that information.128 Justice Marshall said as

much in dissent in Smith v. Maryland,where he argued that “privacy is not a discrete commodity,

possessed absolutely or not at all.”129 He continued: “Those who disclose certain facts to a bank

or phone company for a limited business purpose need not assume that this information will be

released to other persons for other purposes.”130 Several commentators have similarly argued that

there is an important distinction between information that is broadcast to the world and that which

is disclosed in a controlled environment.131 The first category, they argue, includes instances

where the government accesses information that is readily available in the public square, such as

information posted on a publicly available website or a loud conversation overheard in an

airport.132 Because the person has decided to release this information to the public, he cannot later

claim to have an expectation of privacy. The latter category, on the other hand, entails a more

limited sharing that is “an integral part of a legitimate transaction” between the individual and the

recipient of the information, and is entitled to Fourth Amendment protection.133

Along these same lines, some have pointed out the apparent inconsistency in Fourth Amendment

protection accorded to various types of information people share with third parties. In Katz v.

United States and Berger v. New York, the Court held that people have an expectation of privacy

in the content of their conversations,134 while similar protection was not extended to the telephone

128

See Kenneth L. Karst, “The Files”: Legal Controls Over the Accuracy and Accessibility of Stored Personal Data,

31 LAW & CONTEMP. PROBS. 342, 344 (1966).

129

Smith, 442 U.S. at 749 (Marshall, J., dissenting).

130

Id.

131

Susan W. Brenner & Leo L. Clarke, Fourth Amendment for Shared Privacy Rights in Stored Transactional Data, 14

J.L. & POL’Y 211, 258 (2006).

132

Id.

133

Id. This idea that a person loses all Fourth Amendment protection in information he shares with another would seem

to be undermined by various cases in which shared information or spaces did not lose constitutional protection. For

instance, in Minnesota v. Olson, the Court held that an overnight guest could have a reasonable expectation of privacy

in the home of his host, “a place where he and his possessions will not be disturbed by anyone but his host and those

his host allows inside.”133 On the other hand, these cases took place in the context of the home, an area accorded the

highest Fourth Amendment protection, and their holdings might not easily extend to other contexts.

134

Katz v. United States, 389 U.S. 347, 353 (1967); Berger v. New York, 388 U.S. 41, 51 (1967).

Congressional Research Service

17

The Fourth Amendment Third-Party Doctrine

numbers dialed in Smith.135 Dissenting in Smith, Justice Stewart, who authored the Katz majority

opinion, pointed out this incongruity, noting that like telephone numbers, the voice of a

conversation must be transmitted through the telephone company’s equipment and may be

overheard or recorded by that company.136 He argued that “what the telephone company does or

might do with those numbers is no more relevant to this inquiry than it would be in a case

involving the conversation itself.”137 Instead, Justice Stewart would have granted both forms of

information protection under Katz.138 In a line that would foreshadow more recent arguments

against the third-party doctrine, Justice Stewart contended that people are not concerned about

revealing a list of their telephone calls because it could be incriminating, but rather because it

would “reveal the most intimate details of a person’s life.”139

The second major argument against the third-party doctrine challenges the idea that people

“voluntarily” convey information to others when engaging in business transactions. In Miller, the

Court asserted that the financial statements and deposit slips were “voluntarily conveyed” to the

banks in the “ordinary course of business,”140 and in Smith the defendant “voluntarily conveyed

numerical information to the telephone company.”141 More recently, a federal court of appeals

judge made a similar argument regarding cell phone users:

Their use of their phones, moreover, is entirely voluntary. The Government does not require

a member of the public to own or carry a phone. As the days of monopoly phone companies

are past, the Government does not require him to obtain his cell phone service from a

particular service provider that keeps historical cell site records for its subscribers, either.

And it does not require him to make a call, let alone to make a call at a specific location.142

There has been significant disagreement, however, about how voluntary these transactions really

are. Justice Brennan argued in dissent that “for all practical purposes, the disclosure by

individuals or business firms of their financial affairs to a bank is not entirely volitional, since it is

impossible to participate in the economic life of contemporary society without maintaining a bank

account.”143 Similarly, Justice Marshall argued in Smith that “unless a person is prepared to forgo

use” of the telephone, which for “many has become a personal or professional necessity, he

cannot help but accept the risk of surveillance. It is idle to speak of ‘assuming’ risks in contexts

where, as a practical matter, individuals have no realistic alternative.”144 One commentator has

argued that unlike the undercover agent cases, where refusing to talk to a particular individual is a

“realistic option,” refusing to get medical treatment or an education would lead to an

“unproductive” and “possibly much foreshortened existence.”145

135

Smith, 442 U.S. at 745.

Id, at 746 (Stewart, J., dissenting).

137

Id. at 747 (1979) (Stewart, J., dissenting).

138

Id.

139

Id. at 748 (Stewart, J., dissenting).

140

United States v. Miller, 425 U.S. 435, 442 (1976).

141

Smith, 442 U.S. 442 U.S. 744.

142

In re Application of the United States of America for Historical Cell Site Data, 724 F.3d 600, 613 (5th Cir. 2013)

(internal citation omitted),

143

United States v. Miller, 425 U.S. 435, 451 (1973) (Brennan, J., dissenting) (quoting Burrows v. Superior Court, 13

Cal. 3d 238, 247 (1974)).

144

Smith, 442 U.S. at 750 (Marshall, J., dissenting).

145

Slobogin, supra note 7, at 156.

136

Congressional Research Service

18

The Fourth Amendment Third-Party Doctrine

The third central argument against the third-party doctrine challenges the assertion that people

“assume the risk” when handing information over to third parties. People do not assume legal

risks as a matter of pure deduction, the argument goes, “but assume only those risks of

unregulated government intrusion that the courts tell us we have to assume.”146 Dissenting in

White, Justice Harlan expressed concern about the process by which courts determine how much

privacy protection people should expect and will receive. He notes that people’s expectations of

privacy and the risks they assume are “reflections” of the laws handed down by courts or

legislatures. Because it is the “task of the law to form and project, as well as mirror or reflect,”

Justice Harlan instructs, “we should not, as judges, merely recite the expectations and risks

without examining the desirability of saddling them upon society.”147 Instead of allowing “the

substitution of words for analysis,” courts should assess “the nature of a particular practice and

the likely extent of its impact on the individual’s sense of security balanced against the utility of

the conduct as a technique of law enforcement.”148 In other words, rather than simply applying

the phrase “assumption of the risk” in each new legal context, Justice Harlan suggested that

courts should look anew at each surveillance practice and determine its actual impact on the

individual’s privacy interests.149 One commentator has suggested a similar approach in that the

government should not have “practically unrestricted access” to people’s records, or, on the

flipside, that probable cause must be required for every request of documents. Instead, he argues

that the level of protection should depend on the nature of the documents requested.150 For

example, certain types of records, including public records, may not be entitled to the same

protection as others, such as medical or financial records.151

Lastly, many practical arguments have been formulated against application of third-party

doctrine. Justice Harlan believed one of the main concerns with the third-party doctrine was its

ability to breed distrust in people who are communicating with others. He noted that the practice

of third-party bugging “undermine[s] the confidence and sense of security in dealing with one

another that is characteristic of individual relationships between citizens in a free society.”152 In

Justice Harlan’s view, “words would be measured a good deal more carefully and communication

inhibited if one suspected his conversations were being transmitted and transcribed.”153 One only

146

Id. at 157; see also Stephen E. Henderson, The Timely Demise of the Fourth Amendment Third Party Doctrine, 96

IOWA L. REV. BULL. 39, 47 (“It is the law that defines what risks we do and do not assume.”) .

147

White, 401 U.S. at 786 (Harlan, J., concurring). A similar, and more general, criticism has been posed against the

Katz ‘s reasonable expectation of privacy test. Some have argued that it in determining which expectations of privacy

are reasonable, judges are merely imposing their own views of privacy on society. See United States v. Jones, 132 S.

Ct. 945, 962 (2012) (Alito, J., concurring) (“The Katz expectation-of-privacy test ... is not without its own difficulties.

It involves a degree of circularity, and judges are apt to confuse their own expectations of privacy with those of the

hypothetical reasonable person to which the Katz test looks.”); Minnesota v. Carter, 525 U.S. 83, 97 (1998) (Scalia, J.,

concurring) (“In my view, the only thing the past three decades have established about the Katz test ... is that,

unsurprisingly, those ‘actual (subjective) expectation[s] of privacy’ ‘that society is prepared to recognize as

‘reasonable,’’ bear an uncanny resemblance to those expectations of privacy that this Court considers reasonable.”).

148

United States v. White, 401 U.S. 745, 786 (1971) (Harlan, J., concurring).

149

See Catherine Hancock, Warrants for Wearing a Wire: Fourth Amendment Privacy and Justice Harlan’s Dissent in

United States v. White, 79 MISS. L. J. 35 (2009). Similar to Justice Harlan’s comments, the majority in Smith v.

Maryland observed that if people’s subjective expectations of privacy becomes conditioned by government practices

that were “alien to well-recognized Fourth Amendment freedoms,” that a “normative inquiry would be proper” in

determining what constituted a “legitimate expectation of privacy.” Smith, 442 U.S. at 740-41 n.5.

150

Slobogin, supra note 7, at 157.

151

Slobogin, supra note 7, at 157.

152

White, 401 U.S. at 787 (Harlan, J., dissenting).

153

Id.

Congressional Research Service

19

The Fourth Amendment Third-Party Doctrine

has to look to the recent NSA controversy as a more modern example. Some argue that

knowledge that information shared with tech companies like Google, Facebook, and Apple might

end up in the hands of the government has the potential to engender distrust and cost American

businesses significant revenues both at home and abroad.154

Implications of United States v. Jones on the ThirdParty Doctrine

In addition to the doctrinal and practical arguments made against the third-party doctrine, several

concurring opinions in the recent GPS tracking case United States v. Jones prompt additional

questions about its continued application. Some argue that these opinions foreshadow a shift in

the Court’s thinking about the effect of technology on the government’s ability to collect large

data sets about American citizens.

In Jones, the police attached a GPS tracking device to the underbelly of Jones’s car and tracked it

24 hours a day for 28 days without a warrant.155 Under controlling precedent, a person had no

reasonable expectation of privacy when traveling on public streets because he has revealed his

movements to the public at large.156 While it appeared that Jones required a strict application of

this previous case law, the Court ruled 9-0 against the government, and held that the investigative

activity there constituted a Fourth Amendment search. The reason why, however, was far from

unanimous.

The majority opinion, written by Justice Scalia, and joined by Chief Justice Roberts and Justices

Kennedy, Thomas, and Sotomayor, held that the physical attachment of the tracking device on

Jones’s car, coupled with the intent to obtain information about his movements, amounted to a

Fourth Amendment search.157 When the police attached the device, they physically trespassed

onto his vehicle, his “effect,” a constitutionally protected area under the Fourth Amendment’s

protection of “persons, houses, papers, and effects.”158 As Justice Scalia’s opinion relied upon a

trespass theory of the Fourth Amendment, it will likely not have major repercussions for the thirdparty doctrine, unless one accepts that the government trespasses on an individual’s “papers” or

“effects” when it accesses records from third-party companies.159

154

See John Naughton, Edward Snowden’s Not the Story, the Internet Is, THE GUARDIAN (July 23, 2013), available at

http://www.theguardian.com/technology/2013/jul/28/edward-snowden-death-of-internet; Allan Holmes, NSA Spying

Disclosures Could Cost Companies Billions (Sept. 10, 2013), available at http://www.salon.com/2013/09/10/

nsa_spying_disclosures_could_cost_companies_billions_in_sales_newscred/.

155

United States v. Jones, 132 S. Ct. 945, 948 (2012). The D.C. Metropolitan police had obtained a warrant, but it had

expired the day before the device was installed and was installed in the wrong jurisdiction. Id. at n.1.

156

United States v. Knotts, 460 U.S. 276, 281 (1983).

157

Jones, 132 S. Ct. at 949.

158

Id. at 949; U.S. CONST. amend. IV.

159

See Smith, supra note 15, at 571 (“One possibility is that Scalia’s physical trespass analysis applies to digital

trespass. After all, if an agent were to digitally connect with your computer, GPS device, or mobile phone for

investigatory purposes, she is appropriating your property for purposes of gathering evidence, just like the agents who

placed the tracker on your car.”); Jack Wade Nowlin, The Warren Court’s House Built on Sand: From Security in

Persons, Houses, Papers, and Effects to Mere Reasonableness in Fourth Amendment Doctrine, 81 MISS. L. J. 1017,

1046-47 (2012) (“On the ‘protected interest’ view, one would retain one’s right to security in the papers against

governmental intrusion. The essence of the traditional security in protected interests, grounded in the law of property, is

(continued...)

Congressional Research Service

20

The Fourth Amendment Third-Party Doctrine

However, two concurring opinions in Jones by Justices Sotomayor and Alito might signal the

willingness of five Justices to reevaluate future applications of the third-party doctrine, at least

with respect to pervasive government monitoring. Justice Sotomayor’s solo concurrence provided

the more far-reaching of the two opinions. She directly called into question “the premise that an

individual has no reasonable expectation of privacy in information voluntarily disclosed to third

parties.”160 She observed:

This approach is ill suited to the digital age, in which people reveal a great deal of

information about themselves to third parties in the course of carrying out mundane tasks.

People disclose the phone numbers that they dial or text to their cellular providers; the URLs

that they visit and the e-mail addresses with which they correspond to their Internet service

providers; and the books, groceries, and medications they purchase to online retailers.... I for

one doubt that people would accept without complaint the warrantless disclosure to the

Government of a list of every Web site they had visited in the last week, or month, or year.

But whatever the societal expectations, they can attain constitutionally protected status only

if our Fourth Amendment jurisprudence ceases to treat secrecy as a prerequisite for privacy. I

would not assume that all information voluntarily disclosed to some member of the public

for a limited purpose is, for that reason alone, disentitled to Fourth Amendment protection.161

It seems that Justice Sotomayor, if not prepared to discard the third-party doctrine in whole, is

willing to significantly limit its reach, especially when the government is accessing a wealth of

data about an individual. Again, it should be noted that Justice Sotomayor was the only member

to articulate this more expansive roll-back of the third-party doctrine.

More generally, both Justices Sotomayor and Alito’s opinions could be interpreted to call into

question the continued application of the third-party doctrine insofar as it permits pervasive

government monitoring. In his concurrence, Justice Alito, joined by Justices Ginsburg, Breyer,

and Kagan, found that while short-term monitoring may be permissible under past precedent, “the

use of longer term GPS monitoring in investigations of most offenses impinges on expectations of

privacy.”162 Justice Sotomayor, who joined the majority but also concurred separately, agreed

with Justice Alito’s approach and would have gone even further to find that short-term monitoring

should be prohibited in some instances.163

These five Justices expressed two interrelated concerns. First, they were uneasy about the

government’s ability to gather, analyze, and use an extensive volume of information about each

person’s comings and goings. Justice Sotomayor observed that “GPS monitoring generates a

precise, comprehensive records of a person’s public movements that reflects a wealth of

information about her familial, political, professional, religious, and sexual associations.”164 This

idea, commonly referred to as the “mosaic theory,” posits that the aggregation of information

(...continued)

the right to exclude—which, of course, includes the right to selectively include some individuals while excluding

others. On this view, one has a right to allow some actors access to one’s home or papers while still excluding others—

such as the police. It would thus invade the core of the protected interest for the government to obtain papers through a

third party and search through them—without the owner’s permission.”).

160

Jones, 132 S. Ct. at 957 (Sotomayor, J., concurring).

161

Id.

162

Jones, 132 S. Ct. at 964 (Alito, J., concurring).

163

Id. at 957 (Sotomayor, J., concurring).

164

Jones, 132 S. Ct. at 955.

Congressional Research Service

21

The Fourth Amendment Third-Party Doctrine

about a person can reveal a whole lot more about him than each part in isolation. The Justices

were not the first to espouse this theory. Before the case reached the Supreme Court, the District

of Columbia Court of Appeals below articulated a similar sentiment in finding that the

government’s month-long location tracking constituted a Fourth Amendment search:

Prolonged surveillance reveals types of information not revealed by short-term surveillance,

such as what a person does repeatedly, what he does not do, and what he does ensemble.

These types of information can each reveal more about a person than does any individual trip

viewed in isolation. Repeated visits to a church, a gym, a bar, or a bookie tell a story not told

by any single visit, as does one’s not visiting any of these places over the course of a month.

The sequence of a person’s movements can reveal still more; a single trip to a gynecologist’s

office tells little about a woman, but that trip followed a few weeks later by a visit to a baby

supply store tells a different story. A person who knows all of another’s travels can deduce

whether he is a weekly church goer, a heavy drinker, a regular at the gym, an unfaithful

husband, an outpatient receiving medical treatment, an associate of particular individuals or

political groups—and not just one such fact about a person, but all such facts.165

In addition to this aggregation issue, the Justices expressed concern about the ability of

technology to significantly reduce natural barriers such as limited resources and political

accountability that in the past would have limited law enforcement overreach in the field of

surveillance.166 For Justice Alito, the fact that the government simply could not have tracked a

person’s every movement for a month-long period under traditional law enforcement methods led

him to conclude that the tracking was overly intrusive.167

While Justice Sotomayor directly criticized the third-party doctrine, one could read Justice Alito’s

concurrence as limited solely to monitoring conducted directly by government agents, and not

extending to instances where third parties collect data on individuals. That being said, the

combination of the Jones concurrences has already had an effect in third-party cases in lower

federal courts. For example, the District Court for the District of Columbia applied a variation of

the mosaic theory to invalidate the NSA’s collection of telephone call records.168 Citing to the

Jones concurrences, Judge Richard H. Leon acknowledged that the type of information collected

under the NSA’s metadata program was very similar to that upheld in Smith, “but the ubiquity of

phones has dramatically altered the quantity of information that is now available and, more

importantly, what that information can tell the Government about people’s lives.”169 And, as

described above, judges in certain cell phone location monitoring cases have applied Jones and

the mosaic theory to deem months-long government tracking a Fourth Amendment search.170 In

the long run, it may take a more pertinent set of facts for the Justices to advance the arguments

enunciated in Jones.

165

United States v. Maynard, 615 F.3d 544, 562 (D.C. Cir. 2010).

See Jones 132 S. Ct. at 956 (Sotomayor, J., concurring) (“And because GPS monitoring is cheap in comparison to

conventional surveillance techniques and, by design, proceeds surreptitiously, it evades the ordinary checks that

constrain abusive law enforcement practices: ‘limited police resources and community hostility.’”) (quoting Illinois v.

Lidster, 540 U.S. 419, 426 (2004)).

167

Jones, 132 S. Ct. at 964 (Alito, J., concurring).

168

Klayman v. Obama, 957 F. Supp. 2d 1, 36 (D.D.C. 2013).

169

Id. at 35-36.

170

In re Application of the United States of America for an Order Authorizing the Release of Historical Cell-Site

Information, 809 F. Supp. 2d 113, 126 (E.D.N.Y. 2011).

166

Congressional Research Service

22

The Fourth Amendment Third-Party Doctrine

Congressional Response to the Third-Party Doctrine

Notwithstanding the concurring opinions in Jones, the bulk of Supreme Court and lower federal

court precedent have left most non-content information unprotected by the Fourth Amendment. In

some instances, Congress filled this void by creating varying levels of privacy protection for this

type of non-content information. However, these protections are in the main not as robust as the

warrant requirement, and in some instances, searches may be justified by little more than “official

curiosity.”171

Seven years after the Court handed down Smith and ruled that government access to telephone

toll records was not covered by the Fourth Amendment, Congress enacted as part of the

Electronic Communications Privacy Act of 1986 (ECPA) several provisions requiring the

government to seek a court order before using a pen register or trap and trace device.172 Again,

these devices allow the government to gather dialed telephone numbers and email addressing

information, among other non-content information.173 Under 18 U.S.C. § 3123, a court “shall

issue an ex parte order authorizing the installation and use of a pen register or trap and trace

device ... if the court finds that the attorney for the Government has certified that the information

likely to be obtained by such installation and use is relevant to an ongoing criminal

investigation.”174

A few things should be noted about this provision. First, the “shall” language removes discretion

from the judge; if the judge finds the government has made the required certification, he must

issue the order.175 Second, while the court must ensure that the government has made the proper

certification, ECPA does not require an “independent judicial inquiry into the veracity of the

attested facts.”176 This means that the judge will not make an independent assessment whether the

relevancy standard has been met, but only that the government has made the proper certification.

One district court has noted that “the extremely limited judicial review required by [the pen

register statute] is intended merely to safeguard against purely random use of this device.”177 One

magistrate judge went so far as to describe his role under the pen register statute as a “rubber

stamp” limited to “proofreading errors,” and that “without independent judicial review, the

171

See United States v. Morton Salt Co., 338 U.S. 632, 652 (1950) (describing relevancy standard for subpoenas).

Electronic Communications Privacy Act of 1986, P.L. 99-508, § 301, 100 Stat 1848.

173

As enacted in 1986, the pen register statute, by its terms, only authorized the interception of telephone metadata. 100

Stat. 1871 (“[T]he term ‘pen register’ means a device which records or decodes electronic or other impulses which

identify the numbers dialed or otherwise transmitted on the telephone line to which such device is attached.”)

(emphasis added). Congress extended the pen register/trap and trace authority to also cover Internet addressing

information as part of the United and Strengthening America by Providing Appropriate Tools Required to Intercept and

Obstruct Terrorism (USA PATRIOT Act) of 2001, P.L. 107-56, §216, 115 Stat. 272, 288, codified at 18 U.S.C. § 3127.

174

18 U.S.C. § 3123.

175

See United States v. Fregoso, 60 F.3d 1314, 1320 (8th Cir. 1995) (“The judicial role in approving use of trap and

trace devices is ministerial in nature because, upon a proper application being made under 18 U.S.C. § 3122, ‘the

court shall enter an ex parte order authorizing the installation’ of such a device. 18 U.S.C. § 3123(a)”) (emphasis in

original)).

176

In re Application of the United States of America for an Order Authorizing the Installation and Use of a Pen

Register and Trap and Trace Device, 846 F. Supp. 1555, 1559 (M.D. Fla. 1994); see also S. Rpt. 99-541, at 47 (1986)

(“[Section 3123] does not envision an independent judicial review of whether the application meets the relevance

standard, rather the court needs only to review the completeness of the certification submitted.”).

177

United States v. Hallmark, 911 F.2d 399, 402 (10th 1990).

172

Congressional Research Service

23

The Fourth Amendment Third-Party Doctrine

authorization of pen registers is subject to misuse and abuse.”178 Third, the relevancy standard,

which again the government, and not the court, determines if it has been met, is a “far from

burdensome” legal standard.179 The Supreme Court has held, at least in the subpoena context, that

information sought is not relevant only if “there is no reasonable possibility that the category of

materials the Government seeks will produce information relevant to the general subject” of the

investigation.180 In light of this relatively lax standard, several prominent commentators on

privacy and technology have suggested that Congress should increase the evidentiary threshold

under Section 3123 from mere relevance to at least a reasonable suspicion standard similar to that

used for accessing certain stored communications.181

Also included in ECPA is the Stored Communications Act (SCA), in which Congress provided

varying degrees of protection to information historically subject to the third-party doctrine and,

thus, outside the reach of the Fourth Amendment. Under 18 U.S.C. § 2703(c), service providers

must hand over “records or other information pertaining to a subscriber” so long as the

government can establish “specific and articulable facts” that the records are “relevant and

material” to an ongoing criminal investigation.182 This is akin to the Terry reasonable suspicion

standard—it is lower than probable cause but does require the government to articulate its basis to

believe that the information is connected to criminal activity.183 This standard has been applied to

data such as the to/from address line in an email or the IP addresses of websites a person has

visited. Some courts have construed Section 2703(d) in conjunction with the pen register statute

to allow the government access to cell site location information.184 Section 2703(c)(2) requires

the providers to hand over other customer information such as their name, address, telephone

calling records, length of service, telephone number, and means and source of payments,

including credit card or bank account numbers with either an administrative, grand jury, or trial

subpoena.185

Additionally, Congress has passed more targeted privacy protection laws. For instance, the

privacy of cable subscribers is safeguarded under the Cable Communications Privacy Act of

1984,186 and the privacy of video store customers under the Video Privacy Protection Act.187

178

In re Application of the United States of America for an Order Authorizing the Installation and Use of a Pen

Register and Trap and Trace Device, 846 F. Supp. 1555, 1564-65, 1563 n.4 (M.D. Fla. 1994).

179

In Re of Applications of the United States of America for Orders (1) Authorizing the Use of Pen Registers and Trap

and Trace Devices and (2) Authorizing Release of Subscriber Information, 515 F. Supp. 2d 325, 329 (E.D.N.Y. 2007).

180

United States v. R. Enterprises, Inc., 498 U.S. 292, 301 (1991).

181

See Anti-Terrorism Investigations and the Fourth Amendment After September 11, 2001: Hearing Before the

Subcomm. on the Constitution of the H. Comm. of the Judiciary, 108th Cong. 21, 26 (2003) (statements of James

Dempsey, Center for Democracy and Technology, and Orin S. Kerr, Law Professor).

182

18 U.S.C. § 2703(d).

183

In re Application of the United States of America for an Order Pursuant to 18 U.S.C. § 2703(d), 707 F.3d 283, 287

(4th Cir. 2013).

184

In re Application of the United States of America for an Order for Disclosure of Telecommunications Records and

Authorizing the Use of a Pen Register and Trap and Trace, 405 F. Supp. 2d 435, 449-50 (S.D.N.Y. 2005).

185

18 U.S.C. § 2703(c)(2).

186

47 U.S.C. § 551; see Kerr, supra note 123, at 855 (“A broader look at the legal standards that govern criminal

investigations involving new technologies suggests that Congress has often taken the lead, and that judicial decisions

interpreting the Fourth Amendment generally have played a secondary role”).

187

18 U.S.C. § 2710.

Congressional Research Service

24

The Fourth Amendment Third-Party Doctrine

More recently, various Members of Congress have sought to temper the reach of the third-party

doctrine with respect to transactional data. Several days after the Edward Snowden leaks became

public, Senator Paul filed the “Fourth Amendment Restoration Act of 2013” (S. 1121) in an effort

to “stop the National Security Agency from spying on citizens of the United States[.]”188 This bill

would require that “[t]he Fourth Amendment to the Constitution shall not be construed to allow

any agency of the United States Government to search the phone records of Americans without a

warrant based upon probable cause.”189 While dictating to the judiciary what the Fourth

Amendment should and should not protect may be beyond Congress’s constitutional power,190

Congress clearly can play a role in setting substantive and procedural limitations on government

surveillance authorities. For instance, Senator Paul has introduced a similar bill, the “Fourth

Amendment Preservation and Protection Act of 2013” (S. 1037), which would prohibit federal,

state, and local government officials from accessing information relating to an individual held by

a third party in a “system of records.”191 Other congressional measures would alter the third-party

doctrine in a more targeted way. Several location monitoring bills would, for instance, prohibit

companies from sharing their customers’ location information unless the government obtained a

warrant or one of several limited exceptions applied.192

Conclusion

So what does the future have in store for the third-party doctrine and the government’s collection

of non-content, transactional data? At this point, there appears to be only one solid vote on the

Court in Justice Sotomayor for eliminating or significantly reducing the scope of this doctrine.

Although there are hints in Justice Alito’s Jones opinion that he and the three members of his

concurrence are ready to reconsider this rule when it comes to pervasive government surveillance,

his rationale was left somewhat underdeveloped. It will take future opinions to get a better sense

of whether or how far these Justices are willing to go to limit government access to non-content

information held in the hands of third parties. In the meantime, the lower federal courts might

continue to limit or distinguish the third-party doctrine in specific and narrow instances. For

instance, in the NSA telephone metadata case, Judge Leon limited Smith to its facts and held that

it did not apply to this more comprehensive data collection program.193 Likewise, if and when the

Supreme Court is asked to reconsider the scope of the third-party doctrine, it is more likely to

carve out specific exceptions than to overturn it in its entirety. This approach would permit the

courts to engage in a more nuanced, normative approach to analyzing the privacy interests

implicated by accessing records derived from transactions between people and other various

entities.

Another possibility is for Congress to act. Justice Alito observed in Jones that “[i]in

circumstances involving dramatic technological change, the best solution to privacy concerns

188

Fourth Amendment Restoration Act of 2013, S. 1121 (1st Sess. 2013).

189

Id.

190

See Dickerson v. United States, 530 U.S. 428, 437 (2000) (“Congress may not legislatively supersede our decisions

interpreting and applying the Constitution.”).

191

Fourth Amendment Preservation and Protection Act of 2013, S. 1037, 113th Cong. (1st Sess. 2013).

192

See, e.g., Geolocation Privacy and Surveillance Act, S. 639, H.R. 1312, 113th Cong (1st Sess. 2013).

193

Klayman, 957 F. Supp. 2d at 37 (“[T]he Smith pen register and the ongoing NSA Bulk Telephony Metadata Program

have so many significant distinctions between them that I cannot possibly navigate these uncharted Fourth Amendment

waters using as my North Star a case that predates the rise of cell phones.”).

Congressional Research Service

25

The Fourth Amendment Third-Party Doctrine

may be legislative” as “a legislative body is well situated to gauge changing public attitudes, to

draw detailed lines, and to balance privacy and public safety in a comprehensive way.”194 This

argument that Congress is best suited to address the nuanced policy questions that privacy and

security entails has been expressed by commentators as well.195 Like the courts, it appears

unlikely that Congress would be willing to completely eliminate the third-party doctrine. On the

other hand, Congress may be more inclined to engage in a subject-by-subject approach, in which

Congress limits the third-party doctrine in certain areas. Congress provided statutory protection

for telephone toll records in the pen register/trap and trace statute; for Internet metadata in the

Stored Communications Act; and for video customer records in the Video Privacy Protection Act.

It could enact similar protection for other subject areas where non-content information is shared

with companies as a necessary part of doing business.

Author Contact Information

(name redacted)

Legislative Attorney

[redacted]@crs.loc.gov, 7-....

194

195

Jones, 132 S. Ct. at 964.

Kerr, supra note 123, at 857.

Congressional Research Service

26

EveryCRSReport.com

The Congressional Research Service (CRS) is a federal legislative branch agency, housed inside the

Library of Congress, charged with providing the United States Congress non-partisan advice on

issues that may come before Congress.

EveryCRSReport.com republishes CRS reports that are available to all Congressional staff. The

reports are not classified, and Members of Congress routinely make individual reports available to

the public.

Prior to our republication, we redacted names, phone numbers and email addresses of analysts

who produced the reports. We also added this page to the report. We have not intentionally made

any other changes to any report published on EveryCRSReport.com.

CRS reports, as a work of the United States government, are not subject to copyright protection in

the United States. Any CRS report may be reproduced and distributed in its entirety without

permission from CRS. However, as a CRS report may include copyrighted images or material from a

third party, you may need to obtain permission of the copyright holder if you wish to copy or

otherwise use copyrighted material.

Information in a CRS report should not be relied upon for purposes other than public

understanding of information that has been provided by CRS to members of Congress in

connection with CRS' institutional role.

EveryCRSReport.com is not a government website and is not affiliated with CRS. We do not claim

copyright on any CRS report we have republished.

This is a copy of a public record, reproduced as it was published. It is not legal advice, and it may not be the version a court would rely on. Check the official source before you cite it.

A word about cookies

We need a few to keep you signed in and the library working. The rest help us see which pages people use and where they get stuck. They stay off unless you say yes.