Amicus Curiae Brief — James Harper, Petitioner v. Michael Faulkender, Acting Commissioner of Internal Revenue Service, et al.

No. 24-922

In the Supreme Court of the United States

__________

JAMES HARPER,

Petitioner,

v.

DOUGLAS O’DONNELL, IN HIS OFFICIAL CAPACITY AS

ACTING COMMISSIONER OF THE INTERNAL REVENUE

SERVICE; INTERNAL REVENUE SERVICE; JOHN

DOE IRS AGENTS 1–10,

Respondents.

__________

On Petition for a Writ of Certiorari to the

United States Court of Appeals for the First Circuit

__________

BRIEF OF THE CATO INSTITUTE AS AMICUS

CURIAE IN SUPPORT OF PETITIONER

__________

Thomas A. Berry

Counsel of Record

Brent Skorup

Laura A. Bondank

CATO INSTITUTE

1000 Mass. Ave., N.W.

Washington, DC 20001

(443) 254-6330

tberry@cato.org

March 28, 2025

i

QUESTIONS PRESENTED

Does the Fourth Amendment permit warrantless

searches of customer records held by third party service providers if the records are contractually owned

by the customer, or if those records enable surveillance

of future behavior? If not, does the third-party doctrine

need to be discarded or modified to prevent such

searches?

ii

TABLE OF CONTENTS

QUESTIONS PRESENTED ......................................... i

TABLE OF AUTHORITIES ....................................... iv

INTEREST OF AMICUS CURIAE ............................. 1

SUMMARY OF ARGUMENT ..................................... 2

ARGUMENT ................................................................ 6

I. FAILURE TO DETERMINE

OWNERSHIP OF DIGITAL

RECORDS CONSTITUTES

REVERSIBLE ERROR. .................................. 6

A. Courts Must Evaluate Property

Rights in Fourth Amendment

Cases. ........................................................... 6

B. Lower Courts Should Not Extend

Katz and the Third-Party Doctrine

to Digital Surveillance Cases. ..................... 8

C. The Courts Below Erred in

Dismissing Harper’s Claim That He

Has a Property Interest in His

Coinbase Records. ...................................... 10

II. COINBASE USERS HAVE A STRONG

ARGUMENT FOR OWNERSHIP OF

THEIR DIGITAL RECORDS. ....................... 12

iii

A. Coinbase’s User Agreement and

Privacy Policy Arguably Recognize

Users’ Ownership of Their Digital

Records. ...................................................... 13

B. Many States—Including Harper’s—

Expressly Recognize Residents’

Ownership of Their Digital Records. ........ 15

CONCLUSION .......................................................... 18

iv

TABLE OF AUTHORITIES

Page(s)

Cases

Bd. of Regents of State Colleges v. Roth, 408

U.S. 564 (1972) ....................................................... 16

Byrd v. United States, 584 U.S. 395 (2018) ........ 12, 13

Carpenter v. United States, 585 U.S. 296

(2018) ...................... 5, 7, 9, 10, 11, 14, 15, 16, 17, 18

Ex parte Jackson, 96 U.S. 727 (1878) ............. 7, 10, 11

Florida v. Jardines, 569 U.S. 1 (2013) .................. 8, 10

Katz v. United States, 389 U.S. 347 (1967) ................. 6

Kyllo v. United States, 533 U.S. 27 (2001) ................ 12

Larthet v. Forgay, 2 La. Ann. 524 (La. 1847) ............. 7

Martino v. Forward Air, Inc., 609 F.3d 1

(1st Cir. 2010) ......................................................... 12

Olmstead v. United States, 277 U.S. 438

(1928) ........................................................................ 7

People v. Seymour, 536 P.3d 1260 (Colo. 2023)

................................................................ 5, 12, 13, 14

Richards v. Wisconsin, 520 U.S. 385 (1997) ............... 6

Riley v. California, 573 U.S. 373 (2014) ................. 6, 9

Smith v. Maryland, 442 U.S. 735 (1979) .................... 8

Soldal v. Cook County, 506 U.S. 56 (1992) ........... 5, 11

United States Trust Co. v. New Jersey, 431

U.S. 1 (1977) ........................................................... 12

United States v. Di Re, 332 U.S. 581 (1948) ............... 5

United States v. Jones, 565 U.S. 400 (2012) ..... 7, 8, 10

v

United States v. Knotts, 460 U.S. 276 (1983) .............. 8

United States v. Miller, 425 U.S. 435 (1976) .............. 8

Ziegler v. Sarasota Police Dep’t, No. 2024-CA001409-NC (Fla. Dist. Ct. App. July 1,

2024) ......................................................................... 5

Statutes

18 U.S.C. § 2703 ........................................................... 4

720 ILL. COMP. STAT. 5/15-1 (2006) ........................... 17

CONN. GEN. STAT. § 53-451(12) (2024) ...................... 17

DEL. CODE tit. 11, § 931(15) (2024) ........................... 17

GA. CODE § 16-9-92 (2023) ......................................... 17

HAW. REV. STAT. § 708-890 (2011) ............................. 17

IOWA CODE § 702.14 (2025) ........................................ 17

KAN. STAT. § 21-3755 (2011) ...................................... 17

KEN. REV. STAT. § 434.840 (2002).............................. 17

KEN. REV. STAT. § 514.010 (2005).............................. 17

LA. STAT. § 73.1 (2019) ............................................... 17

MASS. GEN. LAWS ch. 266, § 30(2) (2025) .................. 17

MD. CODE, CRIM. LAW § 7-101 (2025) ........................ 17

ME. R. CRIM. PROC. 41(d) (2017) ................................ 17

MINN. STAT. § 609.52(1) (2024) .................................. 17

MINN. STAT. § 609.87(6) (2024) .................................. 17

MISS. CODE § 97-45-1(u) (2024) ................................. 17

MONT. CODE § 45-2-101(65) (2023) ............................ 17

N.C. GEN. STAT. § 14-453 (2012)................................ 17

N.D. CENT. CODE § 12.1-06.1-01(3)(h) (2023) ............ 17

vi

N.H. REV. STAT. § 637:2(I) (2010) .............................. 16

N.H. REV. STAT. § 637:2(V) (2010) ............................. 17

N.H. REV. STAT. § 638:16(XVI)(c) (2022) ................... 17

N.J. REV. STAT. § 2C:20-1(g) (2024) ........................... 17

N.Y. PENAL LAW § 156.00(3) (2025) ........................... 17

NEV. REV. STAT. § 205.4755 (2024) ............................ 17

OHIO REV. CODE § 2901.01(10)(a) (2023)................... 17

OR. REV. STAT. § 164.377(j) (2024) ............................ 17

S.C. CODE § 16-16-10(f) (2002) .................................. 17

TENN. CODE § 39-14-601(17) (2024) ........................... 17

TEX. PENAL CODE § 33.01(16) (2023) ......................... 17

UTAH CODE § 76-6-702(5) (2023) ............................... 17

VT. STAT. tit. 13, § 4101(8) (2024) ............................. 17

WIS. STAT. § 943.20(2)(b) (2017) ................................ 17

WYO. STAT. § 6-3-501(a)(x) (2024) ............................. 17

Other Authorities

Brent Skorup, Tech Companies’ Terms of

Service Agreements Could Bring New

Vitality to the Fourth Amendment, HARV. L.

REV. BLOG (Sept. 9, 2024) ........................................ 2

Coinbase Global Privacy Policy, COINBASE

(last updated March 26, 2024) ............................... 15

Hester Peirce, This CAT is a Dangerous Dog,

REALCLEAR POL’Y (Oct. 9, 2019) .............................. 3

Joe Lancaster, Taking $200 Out of an ATM

Should Not Trigger Federal Financial

Surveillance, REASON (Mar. 14, 2025) ..................... 3

vii

National Taxpayer Advocate, If You Resold

the Hottest Ticket of Summer 2023, You

Likely Didn’t Receive a Form 1099-K—But

This Won’t Last Forever & Always, NTA

BLOG (Feb. 20, 2024) ................................................ 3

Orin S. Kerr, A User’s Guide to the Stored

Communications Act, and a Legislator’s

Guide to Amending It, 72 GEO. WASH.

L. REV. 1208 (2004) .................................................. 4

Orin S. Kerr, The Fourth Amendment and

New Technologies: Constitutional Myths

and the Case for Caution, 102 MICH. L. REV.

801 (2004) ................................................................. 7

Peter P. Swire, Katz Is Dead—Long Live

Katz, 102 MICH. L. REV. 904 (2004) ......................... 7

Todd E. Pettys, Judicial Discretion in

Constitutional Cases, 26 J.L. & POL. 123

(2011) ...................................................................... 18

Trevor Burrus & James Knight, Katz Nipped

and Katz Cradled: Carpenter and the

Evolving Fourth Amendment, 2017–2018

CATO SUP. CT. REV. 79 (2018)................................. 15

William Baude & James Y. Stern, The

Positive Law Model of the Fourth

Amendment, 129 HARV. L. REV. 1821 (2016) ......... 16

Constitutional Provisions

U.S. Const. amend. IV ........................................... 6, 10

1

INTEREST OF AMICUS CURIAE1

The Cato Institute is a nonpartisan public policy

research foundation founded in 1977 and dedicated to

advancing the principles of individual liberty, free

markets, and limited government. Cato’s Robert A.

Levy Center for Constitutional Studies was established in 1989 to promote the principles of limited constitutional government that are the foundation of liberty. Toward those ends, Cato publishes books and

studies, conducts conferences, produces the annual

Cato Supreme Court Review, and files amicus briefs.

Cato’s interest in this case arises from its mission

to support the rights that the Constitution guarantees

to all citizens. Amicus has a particular interest in this

case as it concerns the continuing vitality of the Fourth

Amendment and protecting Americans from warrantless searches and seizures of their records.

1 Rule 37 statement: All parties were timely notified before the

filing of this brief. No part of this brief was authored by any

party’s counsel, and no person or entity other than amicus funded

its preparation or submission.

2

SUMMARY OF ARGUMENT

In this “smart” and digitized world, much of what

we do is captured and stored indefinitely. The places

we go (using our phone’s built-in GPS), the news stories we read, our Google search history, our credit card

purchases, the charities we donate to, and even our

gossip and spousal communications—often emailed or

sent via messaging apps—are routinely collected and

stored by commercial companies.2 Today, digital

recordkeeping is the norm and storing our communications and records on servers owned and maintained

by third parties is impossible to avoid.

Digital technologies dramatically reduce the cost

and inconvenience of record collection and analysis.

And this only stokes law enforcement officials’ insatiable appetite for information about citizens. Therefore,

Congress and many federal agencies believe they’ve

found a “cheat code” for pervasive government surveillance: demand warrantless access to our records on the

dubious theory that we have forfeited any property interest or privacy expectation simply by using a digital

service like email or the Internet.

Financial surveillance is a massive and growing

threat to privacy rights and our constitutional order.

In recent years, for instance, regulators and Congress

have required regulated companies to track and give

the government access to records about Americans’

2 See, e.g., Brent Skorup, Tech Companies’ Terms of Service Agree-

ments Could Bring New Vitality to the Fourth Amendment, HARV.

L. REV. BLOG (Sept. 9, 2024), available at https://tinyurl.com/mrshprrt (“An IT professionals’ aphorism—‘there is no

cloud, it’s just someone else’s computer’—suggests the reality: our

digital lives are stored on nondescript server farms and office

parks spread around the world.”).

3

stock trades.3 They have also required Americans to

report small payments between individuals.4 Financial regulators now even target surveillance at residents in particular counties.5 Without judicial enforcement of Fourth Amendment protections, secretive and

suspicionless digital record collection will become a

routine tool of government regulation and control.

The facts of this case are sadly consistent with

these trends. In 2016, the Internal Revenue Service

(IRS) discreetly ordered Coinbase to produce sensitive

information and financial records about millions of its

customers. Coinbase resisted that initial production

order, but eventually the IRS obtained from Coinbase

records about more than 14,000 account holders and

millions of their cryptocurrency transactions. See Pet.

Br. 6. One account holder, James Harper, learned that

the IRS had seized and searched his Coinbase account

records only after the IRS sent him a letter (incorrectly) suggesting he had not paid taxes on his cryptocurrency income. Id.

3 See Hester Peirce, This CAT is a Dangerous Dog, REALCLEAR

POL’Y (Oct. 9, 2019), available at https://tinyurl.com/b88464f8 (describing the Security and Exchange Commission’s “consolidated

audit trail” system).

See National Taxpayer Advocate, If You Resold the Hottest

Ticket of Summer 2023, You Likely Didn’t Receive a Form 1099K—But This Won’t Last Forever & Always, NTA BLOG (Feb. 20,

2024) (noting that “[i]n 2021, Congress passed the American Rescue Plan Act of 2021 (ARPA), which substantially lowered the filing threshold . . . . for issuing Form 1099-K” from $20,000 to

$600).

4

5 See Joe Lancaster, Taking $200 Out of an ATM Should Not Trig-

ger Federal Financial Surveillance, REASON (Mar. 14, 2025),

available at https://tinyurl.com/3ed93a32.

4

In 2020, Harper sued to protect his privacy and

compel the IRS to delete their copies of his Coinbase

account records. Those retained copies include records

of his “wallet addresses” and “public keys,” which give

the agency “a permanent means to monitor Harper’s

historical and future financial activity.” Id. at 9. Harper asserts that his Coinbase account records are

owned by him and, therefore, that the IRS needed a

warrant to seize and search his records. However, after a perfunctory review of his arguments, the district

court and the appellate court below held that Harper’s

records are owned by Coinbase and, therefore, are

within the third-party exception to the Fourth Amendment’s warrant requirement. See id. at 7–9.

This case demonstrates that the third-party doctrine is outdated and increasingly unworkable. Since

the doctrine’s formalization almost 50 years ago, the

government has relied on it to circumvent the warrant

requirement and obtain Americans’ most sensitive records, including emails, Google search histories, financial records, and location histories.6 Government demands for Americans’ most sensitive records increasingly conflict with the Fourth Amendment’s central

aim, which is “to place obstacles in the way of a too

6 For instance, the Stored Communications Act allows govern-

ment officials to obtain electronic communications stored remotely for longer than 180 days with a subpoena instead of a warrant. See 18 U.S.C. § 2703(a)–(d). The origination of this threshold is unclear but the “strange ‘180 day’ rule . . . may reflect the

Fourth Amendment abandonment doctrine at work.” Orin S.

Kerr, A User’s Guide to the Stored Communications Act, and a

Legislator’s Guide to Amending It, 72 GEO. WASH. L. REV. 1208

(2004).

5

permeating police surveillance.” United States v. Di

Re, 332 U.S. 581, 595 (1948).

This Court has been clear that the Fourth Amendment protects our property. Soldal v. Cook County, 506

U.S. 56, 62 (1992) (“[O]ur cases unmistakably hold

that the Amendment protects property as well as privacy.”). Courts must determine whether an individual

has a property interest in the searched or seized items.

If so, a warrant is required. Yet the district court hastily invoked the third-party doctrine to declare Harper’s

property interest nonexistent, and the First Circuit affirmed.

“[C]ourts are pretty rusty at applying the traditional [property] approach” in Fourth Amendment

cases. Carpenter v. United States, 585 U.S. 296, 398

(2018) (Gorsuch, J., dissenting). However, judges need

not fly blind—many states define digital records as

private property, and some service providers grant

ownership to customers. Americans are beginning to

assert ownership of their digital records in Fourth

Amendment cases, and some state courts are agreeing

that customers own their digital records. See People v.

Seymour, 536 P.3d 1260, 1273 (Colo. 2023) (holding

that Google “users own their Google content” for

Fourth Amendment purposes); Ziegler v. Sarasota Police Dep’t, No. 2024-CA-001409-NC (Fla. Dist. Ct. App.

July 1, 2024).

This Court should grant the petition, reverse the

decision below, and clarify that courts cannot mechanically apply the third-party doctrine when someone

makes a plausible claim of ownership of digital records

seized or searched by the government.

6

ARGUMENT

I.

FAILURE TO DETERMINE OWNERSHIP OF

DIGITAL

RECORDS

CONSTITUTES

REVERSIBLE ERROR.

The Fourth Amendment states that “[t]he right of

the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and

seizures, shall not be violated” and requires that warrants have “probable cause, supported by Oath or affirmation, and particularly describ[e] the place to be

searched, and the persons or things to be seized.” U.S.

CONST. amend. IV.

This Court has noted “that the Fourth Amendment

was the founding generation’s response to the reviled

‘general warrants’ and ‘writs of assistance’ of the colonial era, which allowed British officers to rummage

through homes in an unrestrained search for evidence

of criminal activity.” Riley v. California, 573 U.S. 373,

403 (2014). Further, “[t]he purpose of the Fourth

Amendment’s requirement of reasonableness is to preserve that degree of respect for the privacy of persons

and the inviolability of their property that existed

when the provision was adopted—even if a later, less

virtuous age should become accustomed to considering

all sorts of intrusion ‘reasonable.’” Richards v. Wisconsin, 520 U.S. 385, 392 n.4 (1997) (cleaned up). Lower

courts have not always evaluated Fourth Amendment

challenges with that history in mind.

A. Courts Must Evaluate Property Rights in

Fourth Amendment Cases.

Prior to Justice Harlan’s concurrence in Katz v.

United States, 389 U.S. 347 (1967), when people challenged the validity of a warrantless search, courts

7

focused on property interests. This Court acknowledged that “our Fourth Amendment jurisprudence

was tied to common-law trespass, at least until the latter half of the 20th century.” United States v. Jones,

565 U.S. 400 (2012). See also Olmstead v. United

States, 277 U.S. 438, 458–66 (1928) (citing cases); Ex

parte Jackson, 96 U.S. 727, 733 (1878) (establishing

that the postal service needs a warrant before examining unopened mail and packages); Larthet v. Forgay, 2

La. Ann. 524, 525 (La. 1847) (holding that warrantless

entry into a man’s shop and apartment to look for stolen jewelry is an unreasonable search).

Then, in the mid-20th century, the Court seemingly

“abandoned” the “property regime” and instead

adopted Katz’s reasonable expectation of privacy test.

Peter P. Swire, Katz Is Dead—Long Live Katz, 102

MICH. L. REV. 904, 904–05 (2004). The reasonable expectation of privacy test became the “‘lodestar’ for determining whether a ‘search’ had occurred” within the

meaning of the Fourth Amendment. Carpenter, 585

U.S. at 346 (Thomas, J., dissenting). But the limits of

Katz became apparent as government surveillance

technologies and methods advanced. See Orin S. Kerr,

The Fourth Amendment and New Technologies: Constitutional Myths and the Case for Caution, 102 MICH.

L. REV. 801, 808 (2004).

This Court recognized Katz’s limited scope in

United States v. Jones, 565 U.S. 400 (2012). In Jones,

the suspect challenged the government’s warrantless

installation of a GPS tracking device on his vehicle as

a violation of his Fourth Amendment rights. Id. at 403.

The Court declined to apply the reasonable expectation of privacy test and instead relied on its traditional

property-based analysis—concluding that the officers

8

violated the Fourth Amendment by intruding upon a

constitutionally protected area. Id. at 410.

Jones signaled the rebirth of property rights as a

touchstone of the Fourth Amendment. Writing for the

majority, Justice Scalia explained: “Katz did not erode

the principle ‘that, when the Government does engage

in physical intrusion of a constitutionally protected

area in order to obtain information, that intrusion may

constitute a violation of the Fourth Amendment.’” Id.

at 407 (quoting United States v. Knotts, 460 U.S. 276,

286 (1983) (Brennan, J., concurring)). To hold otherwise would be to “narrow the Fourth Amendment’s

scope.” Id. at 408. The Court reemphasized the importance of analyzing property concepts in Fourth

Amendment search cases just one year after Jones. In

Florida v. Jardines, 569 U.S. 1 (2013), the Court again

endorsed the property-based approach over Katz.

B. Lower Courts Should Not Extend Katz

and the Third-Party Doctrine to Digital

Surveillance Cases.

Although Jones and Jardines reaffirmed the importance of property rights, lower courts too often resort to the Katz test—and the derivative “third party

doctrine”—in Fourth Amendment cases involving sensitive records. Decades ago, this Court said that certain information that people turn over to commercial

companies can be obtained by the government and

searched without a warrant. See United States v. Miller, 425 U.S. 435 (1976) (holding that a depositor had

no legitimate expectation of privacy concerning certain

financial records held by a bank); Smith v. Maryland,

442 U.S. 735 (1979) (holding that a suspect had no legitimate expectation of privacy concerning phone

9

numbers he “conveyed” to a phone company via dialing

phone numbers).

But this Court has not upheld a warrantless search

or seizure under the third-party doctrine since Smith

and Miller. Further, to the extent that the third-party

doctrine is viable, the Court has made clear in recent

cases involving searches of digital records that the government’s analogies to the pre-digital, “manual” era of

government surveillance often do not apply. See Riley,

573 U.S. at 386; Carpenter, 585 U.S. at 312 (“[T]he retrospective quality of the data here gives police access

to a category of information otherwise unknowable. In

the past, attempts to reconstruct a person’s movements were limited by a dearth of records and the frailties of recollection . . . . Whoever the suspect turns out

to be, he has effectively been tailed every moment of

every day for five years.”).

In Riley, for instance, the Court prohibited the warrantless search of a digital storage device (both a

“smart phone” and, in a companion case, a “flip

phone”). In its decision, the Court rejected the government’s extrapolation of legal precedents regarding traditional, often physical, records to digital records. Riley, 573 U.S. at 386. This Court, notably, cited government searches of years’ worth of financial records as

the troubling example of the invasive warrantless

searches that would follow from the government’s impermissible extrapolation from precedent: “The fact

that someone could have tucked a paper bank statement in a pocket does not justify a search of every bank

statement from the last five years.” Id. at 400.

Setting aside the viability of the third-party doctrine in digital records, the property approach allows

courts to “keep easy cases easy.” Jardines, 569 U.S. at

10

11. This traditional approach is not “hobbled by Smith

and Miller, for those cases are just limitations on Katz,

addressing only the question whether individuals have

a reasonable expectation of privacy in materials they

share with third parties.” Carpenter, 585 U.S. at 398

(Gorsuch, J., dissenting) (emphasis removed). Instead,

under the property-based approach, “Fourth Amendment protections for your papers and effects do not automatically disappear just because you share them

with third parties.” Id. See also Ex parte Jackson, 96

U.S. at 733.

C. The Courts Below Erred in Dismissing

Harper’s Claim That He Has a Property

Interest in His Coinbase Records.

Our right to be secure in our “persons, houses, papers, and effects” does not “rise or fall” with the reasonable expectation of privacy test. Jones, 565 U.S. at

406; see U.S. CONST. amend. IV. As Justice Gorsuch

has pointed out, “Katz has yielded an often unpredictable—and sometimes unbelievable—jurisprudence.”

Carpenter, 585 U.S. at 394 (Gorsuch, J., dissenting).

There is a better way. Under the property-based approach, courts need only determine whether “a house,

paper, or effect was yours under the law.” Id. at 397. If

so, the Fourth Amendment is triggered. The lower

courts indefensibly ignored these principles and relied

on the third-party doctrine to prematurely dismiss

Harper’s complaint.

Unfortunately, the courts below failed to properly

consider Harper’s property interests. In his appellate

brief and submissions to the district court, Harper repeatedly asserted “contract rights as the basis of his

property interest.” Pet. Br. 25. Yet, “the First Circuit

did not analyze Harper’s contract.” Id. at 26. In

11

refusing to meaningfully assess Harper’s property interest in the digital records, the First Circuit’s Fourth

Amendment analysis remains incomplete.

The text and history of the Fourth Amendment

demonstrates the close relationship between property

rights and the right to be secure in one’s papers and

effects. Soldal, 506 U.S. at 62 (“[O]ur cases unmistakably hold that the Amendment protects property as

well as privacy.”). When a person claims he has a cognizable property interest in something the government

has obtained, the courts cannot simply rebut that assertion with citation to the third-party doctrine. Even

when someone conveys his personal property or records to the government, he may still have a property

interest in them, and they cannot be searched without

a warrant. See Ex parte Jackson, 96 U.S. at 733 (“Letters and sealed packages . . . in the mail are as fully

guarded from examination and inspection . . . as if they

were retained by the parties forwarding them in their

own domiciles.”).

While Katz “suppl[ies] one way to prove a Fourth

Amendment interest,” it is not and “has never been the

only way”—and “[n]eglecting more traditional approaches may mean failing to vindicate the full protections of the Fourth Amendment.” Carpenter, 585 U.S.

at 405 (Gorsuch, J., dissenting). The courts below

erred by shrugging off Harper’s claims that he owns

his Coinbase records.

The trial court decision made only oblique and brief

reference to Coinbase’s terms of service, never referencing the state property laws that govern Harper’s

agreement with Coinbase. Nor, apparently, did the

court admit or request testimony from Coinbase representatives concerning who owned the records seized by

12

the IRS. But such testimony is vital to resolve a dispositive issue like ownership of the records. See Seymour, 536 P.3d at 1273 (citing the testimony of a

Google employee regarding ambiguous terms of service about ownership of search history records). The

district court’s cursory property analysis in this case,

and the First Circuit’s affirmation, is especially confounding considering the court needed to draw all reasonable inferences in Harper’s favor. See Martino v.

Forward Air, Inc., 609 F.3d 1, 2 (1st Cir. 2010).

Individuals must be afforded the same “degree of

privacy against government that existed when the

Fourth Amendment was adopted.” Kyllo v. United

States, 533 U.S. 27, 34 (2001). The lower courts failed

to properly analyze Harper’s ownership interest based

on the terms of the Coinbase agreements.

II. COINBASE USERS HAVE A STRONG ARGUMENT FOR OWNERSHIP OF THEIR DIGITAL RECORDS.

This Court has long recognized that contracts can

create constitutionally protected property. See United

States Trust Co. v. New Jersey, 431 U.S. 1, 19 n.16

(1977). In determining whether a reasonable expectation of privacy exists, this Court has directed lower

courts to reference contract law and positive law as

“[t]he central inquiry” when determining possession of

effects. See Byrd v. United States, 584 U.S. 395, 409

(2018) (interpreting a rental car agreement to determine whether a suspect has a reasonable expectation

of privacy while operating the vehicle). This Court

should likewise make clear that such sources of law

13

are “central” when evaluating someone’s claim of ownership of digital records.

A. Coinbase’s User Agreement and Privacy

Policy Arguably Recognize Users’ Ownership of Their Digital Records.

Like many service providers, Coinbase’s terms of

service allocate property rights in the data, records,

and communications produced by customers in the use

of its services. These property interests are allocated

and managed pursuant to Coinbase’s user agreement

and privacy policy, which “explicitly grant[] [the user]

ownership of his records.” Pet. Br. 24.

This Court recently illustrated how contracts establish property rights for individuals in the context of

the Fourth Amendment. In Byrd v. United States, the

Court rejected the proposition that only drivers listed

on a rental agreement are entitled to Fourth Amendment protection when operating a rental car. 584 U.S.

at 405. The rental contract gave the renter legal authority to possess and control the vehicle. The Court

determined that when she later gave the defendant

permission to drive the car, he was given “lawful possession and control and [the] attendant right to exclude.” Id. at 407. It was based on these contractual

rights that the Court found the defendant possessed a

reasonable expectation of privacy in the vehicle. Id. at

406–07.

Contracts governing digital services likewise convey property interests—thus, Fourth Amendment protections—to users. In People v. Seymour, the Colorado

Supreme Court held that the defendant owned his

Google search history based on the rights afforded to

him by Google’s terms of service. 536 P.3d at 1273.

14

Relying on Google’s privacy policies and user agreements, the court concluded that the defendant—not

Google—owned his search history because the contract

terms granted the defendant the right “to exclude and

to control the dissemination and use of [his] digital

data.” Id. Thus, the government “interfere[d] with [his]

possessory interest” by “infring[ing] on [his] right to

exclude and to control” when it obtained copies of his

digital records. Id.

Seymour and Byrd are instructive because in both

cases, the contracts governing the defendants’ use and

possession also afforded them the right to control access to the property. To be sure, both cases implicated

third parties—the car in Byrd was owned by a rental

company but lawfully possessed by the defendant, and

the search history in Seymour was generated by the

defendant but processed, possessed, and stored by

Google. But just because a third party lawfully possesses property doesn’t mean the possessor owns the

property. See Carpenter, 585 U.S. at 400 (Gorsuch, J.,

dissenting) (discussing bailment concepts and digital

records).

Harper seems to have a property interest in his

Coinbase records even though he did not possess them.

When people use digital financial services, they share

and produce personal information that can be sensitive, intimate, and privileged. That is why companies

like Coinbase provide user agreements and privacy

policies that allocate the bulk of rights to control and

use personal data to customers. At any time, Coinbase

users may request a copy of their personal information, request the deletion of their data, or withdraw

or restrict consent for the processing of their personal

information. Coinbase Global Privacy Policy,

15

COINBASE (last updated March 26, 2024).7 In other

words, users have the right to control how and when

others access their information. This language leaves

the general right to exclude all others from the digital

records with the customer.

The contract-based property interests that apply to

tangible effects and papers also apply to the storage

and dissemination of digital information. Coinbase’s

terms of service appear to give users ownership over

their digital data and records. That means the government cannot seize, store, or otherwise access those records without first obtaining a warrant.

B. Many States—Including Harper’s—Expressly Recognize Residents’ Ownership

of Their Digital Records.

The contractual terms governing user data are not

the only independent source of law supporting Harper’s assertions of ownership in his Coinbase records.

The laws vary, but most states define electronic data

and digital records as private property. Many states

have enacted laws and policies aimed at protecting users’ ability to control how their digital data is stored

and used. See Carpenter, 585 U.S. at 402 (Gorsuch, J.,

dissenting).

Positive law has “illuminate[d] the meaning of constitutional provisions” since the Founding. Trevor Burrus & James Knight, Katz Nipped and Katz Cradled:

Carpenter and the Evolving Fourth Amendment,

2017–2018 CATO SUP. CT. REV. 79, 106 (2018). In the

context of the Takings Clause, the definition of “property” is shaped by “existing rules or understandings

7 Available at https://www.coinbase.com/legal/privacy.

16

that stem from an independent source such as state

law.” Bd. of Regents of State Colleges v. Roth, 408 U.S.

564, 577 (1972). The Takings Clause was not meant to

be limited to the types of property that existed at the

Founding—rather it was meant to protect private

property generally. See William Baude & James Y.

Stern, The Positive Law Model of the Fourth Amendment, 129 HARV. L. REV. 1821, 1843 (2016). By using

positive law as a guide, the Court has better preserved

the original purpose of the Takings Clause and allowed

the definition of property to accord with contemporary

understanding.

For the same reasons, positive law is useful in the

Fourth Amendment context. See Carpenter, 585 U.S.

at 354 (Thomas, J., dissenting) (noting that “positive

law is potentially relevant” to determining property

ownership); id. at 403 (Gorsuch, J., dissenting)

(“[P]ositive law may help provide detailed guidance on

evolving technologies.”). States and the federal government are actively working to enact protections for

third-party data storage and digital privacy. See id. at

402 (Gorsuch, J., dissenting).

It’s unclear which state’s law governs Coinbase’s

terms of service obligations because the courts below

did not ascertain that. However, Harper is a New

Hampshire resident, and the relevant state laws

strengthen his property rights argument. In addition

to its privacy protection act, New Hampshire’s criminal code broadly defines “property” as “anything of

value, including . . . tangible and intangible personal

property.” N.H. REV. STAT. § 637:2(I) (2010) (emphasis

17

added).8 And its law governing computer crimes explicitly defines “property” to include “[f]inancial instruments [and] computer data.” N.H. REV. STAT.

§ 638:16(XVI)(c) (2022). New Hampshire is not alone.

Today, more than half of all states have enacted or

amended laws to include digital records and data in

their definition of property.9

“[I]f state legislators or state courts say that a digital record has the attributes that normally make

something property,” that provides “a sounder basis

for judicial decisionmaking than judicial guesswork.”

Carpenter, 585 U.S. at 402 (Gorsuch, J., dissenting).

State laws make it illegal for private actors to access

or use another person’s digital data. By explicitly defining digital records as “property” and by enacting

8 The New Hampshire law defines “value” as “the highest amount

determined by any reasonable standard of property or services.”

N.H. REV. STAT. § 637:2(V) (2010).

CONN. GEN. STAT. § 53-451(12) (2024); DEL. CODE tit. 11,

§ 931(15) (2024); GA. CODE § 16-9-92 (2023); HAW. REV. STAT.

§ 708-890 (2011); 720 ILL. COMP. STAT. 5/15-1 (2006); IOWA CODE

§ 702.14 (2025); KAN. STAT. § 21-3755 (2011); KEN. REV. STAT.

§ 514.010 (2005); KEN. REV. STAT. § 434.840 (2002); LA. STAT. §

73.1 (2019); ME. R. CRIM. PROC. 41(d) (2017); MD. CODE, CRIM.

LAW § 7-101 (2025); MASS. GEN. LAWS ch. 266, § 30(2) (2025);

MINN. STAT. § 609.52(1) (2024); MINN. STAT. § 609.87(6) (2024);

MISS. CODE § 97-45-1(u) (2024); MONT. CODE § 45-2-101(65)

(2023); NEV. REV. STAT. § 205.4755 (2024); N.J. REV. STAT.

§ 2C:20-1(g) (2024); N.Y. PENAL LAW § 156.00(3) (2025); N.C.

GEN. STAT. § 14-453 (2012); N.D. CENT. CODE § 12.1-06.1-01(3)(h)

(2023); OHIO REV. CODE § 2901.01(10)(a) (2023); OR. REV. STAT.

§ 164.377(j) (2024); S.C. CODE § 16-16-10(f) (2002); TENN. CODE

§ 39-14-601(17) (2024); TEX. PENAL CODE § 33.01(16) (2023);

UTAH CODE § 76-6-702(5) (2023); VT. STAT. tit. 13, § 4101(8)

(2024); WIS. STAT. § 943.20(2)(b) (2017); WYO. STAT. § 6-3501(a)(x) (2024).

9

18

digital privacy statutes that give users the right to obtain, control, and delete their personal information,

states have embraced the position that users often own

their digital records.

It is necessary to rely on “democratically legitimate

sources of law” to ensure that judges don’t replace

sound legal analysis with “their own biases or personal

policy preferences.” Id. at 398 (quoting Todd E. Pettys,

Judicial Discretion in Constitutional Cases, 26 J.L. &

POL. 123, 127 (2011)). Both contract law and state law

support the conclusion that Harper owns his Coinbase

records. The lower courts’ mechanical reliance on the

third-party doctrine elevates government officials and

gives them the power to search and seize digital records in violation of state law and binding contracts.

CONCLUSION

For these reasons, and those described by the

Petitioner, this Court should grant the petition.

........................................... Respectfully submitted,

March 28, 2025

Thomas A. Berry

Counsel of Record

Brent Skorup

Laura A. Bondank

CATO INSTITUTE

1000 Mass. Ave., N.W.

Washington, DC 20001

(443) 254-6330

tberry@cato.org