Amicus Curiae Brief — Aaron Rayshan Wells, Petitioner v. Texas

Supreme Court briefNov 19, 2025

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No. 25-484

In the Supreme Court of the United States

AARON RAYSHAN WELLS, Petitioner,

TEXAS

On Petition for a Writ of Certiorari to

the Texas Court of Criminal Appeals

BRIEF OF AMICUS CURIAE

PROJECT FOR PRIVACY & SURVEILLANCE

ACCOUNTABILITY, INC.

SUPPORTING PETITIONER

GENE C. SCHAERR

Counsel of Record

ERIK S. JAFFE

JUSTIN A. MILLER

SCHAERR | JAFFE LLP

1717 K Street NW, Suite 900

Washington, DC 20006

Telephone: (202) 787-1060

gschaerr@schaerr-jaffe.com

Counsel for Amicus Curiae

November 19, 2025

QUESTIONS PRESENTED

1. Does law enforcement’s collection of digital

location-history data pursuant to geofence warrants

like the one in petitioner’s case violate the Fourth

Amendment?

2. Should the exclusionary rule apply to evidence

derived from the geofence warrant?

TABLE OF CONTENTS

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

INTRODUCTION, SUMMARY, AND

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

STATEMENT .............................................................. 3

ADDITIONAL REASONS FOR GRANTING

THE PETITION ....................................................... 4

II.

This Court Should Grant Review to

Correct Widespread Misinterpretations

of the Post-Carpenter Third-Party

Doctrine. .......................................................... 6

The use of geofence warrants is

exploding.................................................. 6

Lower courts are split on the

applicable Fourth Amendment

standard................................................... 8

Geofenced Data Seizures Are a Fourth

Amendment Search. ..................................... 10

Carpenter’s totality-of-thecircumstances analysis should be

applied in every case. ............................ 10

Carpenter clarifies that turnover to

a third party is only one

consideration affecting expectations

of privacy. .............................................. 12

iii

Seizure of even short-term slices of

comprehensive cell-phone-location

records is incompatible with

Founding Era levels of privacy. ............ 14

III. Geofence Warrants Are

Unconstitutional Because They Are Not

Based on Probable Cause for Most

Individuals Surveilled. ................................. 15

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

TABLE OF AUTHORITIES

Cases

Carpenter v. United States,

585 U.S. 296 (2018) .............................1-2, 6-7, 10-15

Carroll v. United States,

267 U.S. 132 (1925) ................................................ 11

Katz v. United States,

389 U.S. 347 (1967) ................................................ 10

Kyllo v. United States,

533 U.S. 27 (2001) ........................................... 6-7, 11

Maryland v. Shatzer,

559 U.S. 98 (2010) .................................................. 11

Miranda v. Arizona,

384 U.S. 436 (1966) ................................................ 11

Riley v. California,

573 U.S. 373 (2014) .......................................... 13, 15

Sibron v. New York,

392 U.S. 40 (1968) .................................................. 17

Smith v. Maryland,

442 U.S. 735 (1979) ................................................ 10

United States v. Chatrie,

107 F.4th 319 (4th Cir. 2024) ............................ 8, 12

United States v. Chatrie,

136 F.4th 100 (4th Cir. 2025) .................................. 9

United States v. Davis,

109 F.4th 1320 (11th Cir. 2024) .............................. 8

United States v. Miller,

425 U.S. 435 (1976) ................................................ 13

United States v. Smith,

110 F.4th 817 (5th Cir. 2024) .............4-6, 8-9, 15-16

Ybarra v. Illinois,

444 U.S. 85 (1979) .................................................. 17

Rule

Fed. R. Crim. Proc. 20 ................................................. 9

Other Authorities

Decl. of Independence (U.S. 1776) ............................ 17

Haley Amster & Brett Diehl,

Against Geofences, 74 Stan. L. Rev. 385

(2022) ........................................................................ 6

Lukas Haas et al.,

PIGEON: Predicting Image Geolocations, in

Proceedings of the IEEE/CVF Conference on

Computer Vision and Pattern Recognition

(CVPR), 2024, at 12893 (2024) ................................ 7

Proj. for Priv. & Surveillance Accountability,

Inc., Meet America’s Latest Mass

Surveillance Tool: GeoSpy (Aug. 18, 2025) ............. 8

INTRODUCTION, SUMMARY, AND

INTEREST OF AMICUS CURIAE1

This case presents an exceptionally important

Fourth Amendment question: Can the government

demand, without a warrant, a multi-hour slice of a

comprehensive database of numerous individuals’

movements in an effort to track all persons within a

specified geographic area and time? The principles

underlying this Court’s Fourth Amendment caselaw

strongly suggest this increasingly widespread practice

violates the Constitution: It is incompatible, as this

Court put it in Carpenter v. United States, 585 U.S.

296 (2018), with “that degree of privacy against

government that existed when the Fourth Amendment

was adopted.” Id. at 305. But federal and state courts

continue to treat Carpenter as the exception rather

than the rule. And this Court should grant certiorari

to clarify that it meant what it said there.

Carpenter correctly recognized that the Fourth

Amendment protects privacy interests that would

have been recognized as reasonable at the Founding.

Such expectations set the baseline for measuring

modern encroachments on privacy, notwithstanding

advances in technology that make it easier to invade

that privacy. Under such baseline expectations,

merely storing information with third parties, under

contractual assurances of privacy and security, does

1 This brief was not authored in whole or in part by counsel for

any party and no person or entity other than amicus curiae, its

counsel, or its members has made a monetary contribution

toward the brief’s preparation or submission. Counsel of record

for all parties received timely notice of amicus’ intent to file this

brief.

not vitiate reasonable expectations of privacy,

particularly as against the government. Nor do those

privacy expectations cease because the government

demands a shorter view of the comings-and-goings of

the persons within a geofence: The government is still

demanding surveillance of each person within that

fence, essentially amounting to a general warrant.

The Texas Court of Criminal Appeals ignored these

basic principles and this Court’s guidance. It

mistakenly treated temporal and geographic limits on

what is essentially a general search warrant, as well

as limited-purpose storage by a third party (here

Google), as sufficient to destroy any expectation of

privacy that Petitioner Aaron Rayshan Wells had in

his location data. But, as the petition explains, that is

fundamentally wrong. And of course, Wells was not

the only person whose privacy interests were violated

here: As with any geofence warrant, innocent

bystanders were also subject to the government’s

retroactive surveillance of their movements.

Because of the serious privacy issues raised by

geofence warrants, they are of particular concern to

Amicus Curiae Project for Privacy & Surveillance

Accountability, Inc. (PPSA), a nonprofit, nonpartisan

organization dedicated to protecting privacy rights.

PPSA urges this Court to reverse the Texas Court of

Criminal Appeals’ decision and hold that Americans

have a reasonable expectation of privacy in even shortterm portions of long-term tracking databases created

from their confidential information. The Court can

thereby help ensure that Fourth Amendment rights

are not left “at the mercy of advancing technology.”

Carpenter, 585 U.S. at 305 (citation omitted).

STATEMENT

In the underlying case, a detective attempting to

solve a capital murder committed during a robbery

applied for a “geofence warrant” requiring Google to

identify all devices within a geographical area during

a twenty-five-minute interval corresponding with the

approximate time of the offense. Pet.7a. This search

encompassed the house where the incident occurred

and the church grounds and building across the street.

Ibid. Ultimately, Google identified a cell phone

associated with Wells at the scene. Pet.10a. The

detective used Wells’s phone records and social media

to identify three other men involved in the offense, one

of whom ultimately testified as an accomplice witness

against Wells at trial. Pet.10a, 86a-87a. Wells was

charged with capital murder and convicted. He was

sentenced to life without parole. Pet.4a.

When Wells moved to suppress the fruits of the

geofence warrant, the district court wrongly held that

the warrant affidavit and the warrant itself had

“sufficient particularity to be valid” and denied the

motion. Pet.10a-11a.

On appeal, the Texas intermediate court of appeals

affirmed the trial court’s denial of the motion to

suppress because the warrant had sufficient probable

cause or, alternatively, the reliance on the warrant

was objectively reasonable and thus the evidence

admissible under the good-faith exception. Pet.11a12a.

On discretionary review, the Texas Court of

Criminal Appeals ultimately affirmed the court of

appeals, but the seven justices were fractured on why

they thought the search was constitutional. Pet.1a-2a.

Five Justices thought no search occurred. Pet.27a-28a

(Finley, J., concurring) (finding no search); Pet.37a38a (Newell, J., concurring in part and dissenting in

part) (same for first two geofence warrant steps). One

Justice found that a search occurred but was

supported by probable cause and was sufficiently

particularized. Pet.19a-20a (Yeary, J.). For reasons

explained in the petition and below, all of them were

wrong.

ADDITIONAL REASONS FOR GRANTING

THE PETITION

This case presents an enormously important

Fourth Amendment question that has divided federal

and state courts, generating splits between the Fifth

Circuit on one side and the Texas Court of Criminal

Appeals and the Fourth and Eleventh Circuits on the

other. In contrast to the Texas Court of Criminal

Appeals’ decision here, the Fifth Circuit correctly held

that, not only is there an expectation of privacy in

location data, but broad geofence warrants are

inherently unconstitutional. See United States v.

Smith, 110 F.4th 817, 835-838 (5th Cir. 2024), cert.

denied mem., No. 24-7237, 2025 WL 3131804 (U.S.

Nov. 10, 2025). These splits should be resolved now—

especially given that a Texas citizen’s privacy rights

now depend on whether (s)he is charged with a crime

in federal or state court.

In that regard, Amicus agrees with Petitioner (at

13) that the location-history data here is “more

pervasive and precise than the CSLI in Carpenter.”

That is because the location data at issue can “follow

a person from the interior of their home, among the

rooms of their dwelling, to the location of a crime, then

to a place of worship.” Pet.15 (quoting Smith, 110

F.4th at 833). Additionally, rather than tracking a

single person, as in Carpenter, a geofence “will

retroactively track anyone with Location History

enabled, regardless of whether a particular individual

is suspicious or moving within an area that is typically

granted Fourth Amendment protection.” Id. (quoting

Smith, 110 F.4th at 834).

Moreover, the Texas Court of Criminal Appeals’

erroneous application of Carpenter is but one of many

examples of federal and state courts abandoning all

semblance of Founding Era privacy and concluding

that Americans have no Fourth Amendment

protections against a host of intrusive surveillance

practices. That conclusion and similar holdings will

continue to drastically undermine Americans’ privacy

as third-party storage becomes increasingly common

and inescapable.

Amicus writes separately to emphasize that, as

Carpenter clarified, Fourth Amendment protections

are not categorically lost when a person shares or

stores his data with a third party while maintaining

reasonable expectations and assurances of privacy.

The Court should grant review to prevent a contrary

understanding of Carpenter from continuing to erode

Americans’ privacy—especially now, as third-party

storage becomes more ubiquitous and artificial

intelligence becomes powerful enough to piece

together intimate information from seemingly

innocuous details about a target’s life.

This Court Should Grant Review to Correct

Widespread Misinterpretations of the PostCarpenter Third-Party Doctrine.

The Texas Court of Criminal Appeals’ decision, as

well as those of the Fourth and Eleventh Circuits,

contravene this Court’s repeated holdings that the

Fourth Amendment protects “that degree of privacy

against government that existed when [it] was

adopted.” Carpenter, 585 U.S. at 305 (quoting Kyllo v.

United States, 533 U.S. 27, 34 (2001)). This is true in

the context of the third-party doctrine as well,

especially regarding the kind of location data at issue

here—that of all users entering a specific area during

a particular period.

A. The use of

exploding.

geofence

warrants

The warrants here present a significant Fourth

Amendment issue and may determine the geofence

policies of law enforcement agencies throughout the

nation for many years. Far from a minor or occasional

concern, such warrants “have become increasingly

common,” Haley Amster & Brett Diehl, Against

Geofences, 74 Stan. L. Rev. 385, 388 (2022). While the

true number of requests is not known given their

issuance to multiple companies, the burden imposed

by them has become so severe that Google recently

changed its location tracking system to protect itself

and its customers. See Smith, 110 F.4th at 822 n.3.

Beyond the increasing use of such warrants, this

Court has emphasized that courts and law

enforcement personnel have a constitutional duty to

ensure they do not leave the public’s Fourth

Amendment rights ‘“at the mercy of advancing

technology.’” Carpenter, 585 U.S. at 305 (citation

omitted). Rulings made about current technology

should be forward-looking as to their impact on

privacy, and “the rule the Court adopts ‘must take

account of more sophisticated systems that are

already in use or in development.’” Id. at 313 (quoting

Kyllo, 533 U.S. at 36).

Here, systems already in development could enable

even more intrusive forms of geofenced data searches

and seizures. For instance, rather than requesting the

location history of all individuals within a geofence for

further scrutiny, it may soon be possible to request all

photos that seemingly were taken within the geofence.

Even photos that do not ordinarily contain geolocation

data could be scanned for other locational clues and

turned over to law enforcement. Indeed, researchers

have demonstrated that artificial intelligence can

estimate—with surprisingly high accuracy—locations

from mere photographs.2

Those technologies are now operational and in use

by law enforcement. For example, GeoSpy is an AI tool

that can examine a photograph and extrapolate its

location in seconds using only visual data, not

metadata. GeoSpy’s abilities are not limited to outdoor

photographs with identifiable public landmarks. Its

visual model has become so advanced that GeoSpy has

2 See Lukas Haas et al., PIGEON: Predicting Image Geolocations,

in Proceedings of the IEEE/CVF Conference on Computer Vision

and Pattern Recognition (CVPR), 2024, at 12893 (2024),

https://tinyurl.com/5xn5999c.

learned “regional architectural cues,” and can identify

locations from indoor photographs.3

The Texas Court of Criminal Appeals’ reasoning

that a geofence warrant framed narrowly enough will

not infringe privacy rights of an innocent bystander is

missing the point. Pet.19a. As pointed out in Smith,

“[w]hile the results of a geofence warrant may be

narrowly tailored, the search itself is not.” Smith, 110

F.4th at 837. The reasoning of the Texas Court of

Criminal Appeals could justify demands for still more

limited-time slices of geofenced information, such as

all photos or videos in Google’s or Apple’s cloud that

match particular locations and times. The danger to

constitutionally protected privacy, both under present

and future technology, makes this decision ripe for

review.

B. Lower courts are split on the applicable

Fourth Amendment standard.

A split on this issue between the Fifth Circuit and

Texas state courts and among the circuits also

warrants review. The first decision came from the

Fourth Circuit, which held a warrant is not even

required for certain geofence data seizures. United

States v. Chatrie, 107 F.4th 319, 325 (4th Cir. 2024),

aff’d on reh’g en banc, 136 F.4th 100 (4th Cir. 2025),

pet. for cert. docketed, No. 25-112 (U.S. July 30, 2025).

A few weeks later, the Eleventh Circuit agreed. United

States v. Davis, 109 F.4th 1320, 1330 (11th Cir. 2024),

pet. for cert. docketed, No. 25-5189 (U.S. July 24, 2025).

3 Proj.

for Priv. & Surveillance Accountability, Inc., Meet

America’s Latest Mass Surveillance Tool: GeoSpy (Aug. 18, 2025),

https://tinyurl.com/mtwf8cky.

But then the Fifth Circuit correctly split from those

courts and held that geofence warrants and search

requests are unconstitutional in nearly all cases.

Smith, 110 F.4th at 835-838. Then the en banc Fourth

Circuit reconsidered Chatrie but badly fractured and

could not reach a majority decision. United States v.

Chatrie, 136 F.4th 100, 100 (4th Cir. 2025) (en banc)

(per curiam), pet. for cert. docketed, No. 25-5189 (U.S.

July 24, 2025). Now the Texas Court of Criminal

Appeals has disagreed, also badly fracturing into

multiple non-majority opinions. Pet.1a-2a. The court

agreed, however (save for one Justice), that either no

search occurred, Pet.27a-28a (Finley, J., concurring)

(finding no search); Pet.37a-38a (Newell, J.,

concurring in part and dissenting in part) (same for

first two geofence warrant steps), or that a search

occurred but was supported by probable cause and was

sufficiently particularized, Pet.19a-20a (Yeary, J.).

The consequences of this split are exacerbated by

the possibility of “spillover” between conflicting

circuits: A warrant issued in one circuit could lead to

an arrest and trial of a defendant in another circuit.

See, e.g., Fed. R. Crim. Proc. 20 (noting that a

“prosecution may be transferred from the district ***

from which a warrant on a complaint has been issued,

to the district where the defendant is arrested”).

Similarly, a warrant issued in the Texas state system

could lead to an arrest and trial in the federal system.

The existing split and its significant cross-circuit and

state-federal implications are yet further strong

grounds for this Court’s review.

II. Geofenced Data Seizures Are a Fourth

Amendment Search.

On the merits, this Court should reverse the Texas

Court of Criminal Appeals’ decision. That court

assumed but did not decide that a search occurred

here. Pet.13a & n.9. As shown below, that assumption

was correct: A Fourth Amendment search or seizure

occurs when information or items are obtained or

seized, the person has a subjective expectation of

privacy in the information or items searched or

seized,4 and the expectation would have been

recognized as reasonable at the time of the Founding

or is necessary to preserve Founding Era levels of

privacy. See Carpenter, 585 U.S. at 304-305; Katz v.

United States, 389 U.S. 347, 361 (1967) (Harlan, J.,

concurring). Carpenter, moreover, explained that the

reasonableness of an expectation of privacy should be

evaluated using the totality of the circumstances, and

disclosure to a third party is simply one among

multiple circumstances affecting reasonableness. Nor,

as also explained below, is Carpenter restricted to

seizures of longer-term “slices” or “windows” of

movement history.

A. Carpenter’s totality-of-the-circumstances

analysis should be applied in every case.

Carpenter lies “at the intersection of two lines of

cases,” 585 U.S. at 306, that both ultimately address

the same question: Does a reasonable expectation of

privacy exist? Carpenter explains that an expectation

4 A subjective expectation of privacy merely requires “seek[ing] to

preserve something as private.” Smith v. Maryland, 442 U.S. 735,

740 (1979) (cleaned up). This is easily satisfied here.

of privacy is reasonable when it would have been

recognized as reasonable at the Founding or is

necessary to preserve a Founding Era degree of

privacy. See, e.g., id. at 305 (“As technology has

enhanced the Government’s capacity” to surveil, “this

Court has sought to ‘assure * * * preservation of that

degree of privacy against government that existed

when the Fourth Amendment was adopted.’” (quoting

Kyllo, 533 U.S. at 34)).5

To achieve that end, Carpenter evaluates

reasonableness using a totality-of-the-circumstances

formula, with history and certain “guideposts” to be

considered. Id. at 304-305. Just as with other totalityof-the-circumstances tests—such as Miranda—

circumstances in individual cases are factor-like, even

if they do not generate a traditional balancing test.

See, e.g., Maryland v. Shatzer, 559 U.S. 98, 103, 106107 (2010) (citing Miranda v. Arizona, 384 U.S. 436,

456-457 (1966)) (comparing to specific facts in

Miranda).

The Texas Court of Criminal Appeals thus erred by

reducing the relevant circumstances in Carpenter to

mere supporting observations for a more limited rule

restricting Fourth Amendment protections to longterm tracking data. Pet.33a-34a. The court should

have treated Carpenter’s facts as factor-like

circumstances to apply prospectively to any type of

5 See

also Carpenter, 585 U.S. at 304-305 (quoting Carroll v.

United States, 267 U.S. 132, 149 (1925) (footnote omitted)); id. at

320.

personal data the government seeks to access—longterm, short-term, or otherwise.6

Indeed, the Carpenter court explicitly declined the

“parties[’] suggest[ions]” that tracking “becomes a

search only if it extends beyond a limited period” such

as “a 24-hour cutoff.” Carpenter, 585 U.S. at 310 n.3.

And it is unlikely that a 24-hour period would be

qualitatively different than the 25-minute period here,

Pet.7a, in terms of its ability to reveal private

information, such as who a person might have visited,

what meetings they might have gone to, or any other

private information that could easily be revealed by a

25-minute window into a person’s movements. And the

Carpenter Court, despite addressing Justice

Kennedy’s dissent at length, did not challenge his

characterization of the decision as a “multifactor

analysis—considering intimacy, comprehensiveness,

expense,

retrospectivity,

and

voluntariness.”

Carpenter, 585 U.S. at 340 (Kennedy, J., dissenting).

In all events, the varying interpretations of

Carpenter—including competing interpretations that

now apply to the same set of Texas citizens—cry for

this Court’s review of the questions presented here.

B. Carpenter clarifies that turnover to a

third party is only one consideration

affecting expectations of privacy.

Contrary to the reasoning below, third-party access

to data does not inherently trump a claim to Fourth

Amendment protection. Carpenter, 585 U.S. at 309.

6 See Chatrie, 107 F.4th at 333 (quoting Carpenter, 585 U.S. at

310-311).

Instead, Carpenter clarified that the third-party line

of cases always viewed disclosure to a third party as

merely one factor in that inquiry. Id. at 314 (“Smith

and Miller, after all, did not rely solely on the act of

sharing. Instead, they considered ‘the nature of the

particular documents sought’ to determine whether

‘there is a legitimate “expectation of privacy”

concerning their contents.’” (quoting United States v.

Miller, 425 U.S. 435, 442 (1976))).

This is true even if information is knowingly or

voluntarily given to a third party. Carpenter, 585 U.S.

at 314 (“The third-party doctrine partly stems from

the notion that an individual has a reduced

expectation of privacy in information knowingly

shared with another. But the fact of ‘diminished

privacy interests does not mean that the Fourth

Amendment falls out of the picture entirely.’” (quoting

Riley v. California, 573 U.S. 373, 392 (2014))). Indeed,

Carpenter discussed the issue of involuntary

disclosure only as an alternative argument, after

concluding there was a reasonable expectation of

privacy in the data at issue despite being stored by a

third party. See id. at 315 (“Neither does the second

rationale underlying the third-party doctrine—

voluntary exposure—hold up when it comes to [cellsite location information].”).

In short, under Carpenter, the mere fact that

individuals allow some third parties access to data for

particular purposes hardly suggests abandonment of a

reasonable expectation of privacy as to access by

others—especially the government. Letting a plumber

into your house to fix a sink does not mean you have

no expectation of privacy when the police come

knocking.

Here again, the lower courts’ confusion about this

aspect of Carpenter cries out for this Court’s review.

C. Seizure of even short-term slices of comprehensive cell-phone-location records is

incompatible with Founding Era levels of

privacy.

Applying Carpenter’s totality of the circumstances

test shows there is clearly a legitimate expectation of

privacy in the data here, which is nearly identical to

that in Carpenter. Such data allows easy and

inexpensive access to a “deep repository of historical

location information at practically no expense.”

Carpenter, 585 U.S. at 311. It “achieves near-perfect

surveillance,” “runs against everyone,” and allows the

government to “travel back in time to retrace a

person’s whereabouts.” Id. at 312.

The only differences here are nominal knowledge,

nominal supposed consent, and the use of a shorter

slice of an extraordinarily long-term tracking

program. But it is hard to imagine, either at the

Founding Era or even before the digital age, any

ordinary citizen feeling comfortable giving a

government official the ability to glimpse back at a

near-perfect record of years’ worth of the individual’s

movements—even if the window in some cases is only

a few hours, and even if it was nominally voluntarily

disclosed to a corporation.

This Court should thus grant review and then hold

there is a reasonable expectation of privacy in such

data.

III. Geofence Warrants Are Unconstitutional

Because They Are Not Based on Probable

Cause for Most Individuals Surveilled.

The decision below was also wrong for another

reason: Geofence warrants inherently lack the

particularity required by the Fourth Amendment in

all but the most extreme circumstances, e.g., when

every person within the specified geofence satisfies

probable cause for the crime. But the police made no

such showing here.

As this Court has recognized, cellphones are now so

“pervasive and insistent” in modern life that to an

extraterrestrial visitor, they might be mistaken for a

“feature of human anatomy.” Riley, 573 U.S. at 385.

Most Americans “compulsively” carry their phones

constantly. Carpenter, 585 U.S. at 311.

More than half a billion Google users worldwide

also have Google’s opt-out Location History enabled.

See Smith, 110 F.4th at 836. As with the cell-site

location information this Court addressed in

Carpenter, those phones’ location-tracking capabilities

produce a “deep repository of historical location

information” of users’ daily movements accessible with

“just the click of a button” and at “practically no

expense.” Carpenter, 585 U.S. at 311-312.

And just as in Carpenter, because this information

is collected for nearly all users at all times, “police

need not even know in advance whether they want to

follow a particular individual, or when.” Id. at 312. The

resulting system of “near perfect surveillance” is as if

the government had “attached an ankle monitor” to a

significant portion of the American people. Ibid.

As the Fifth Circuit correctly reasoned, the police’s

barging into this trove of intimate information is a

modern incarnation of the “reviled ‘general warrants’

and ‘writs of assistance’ of the colonial era.” Smith, 110

F.4th at 836. General warrants specify an offense but

allow officers the discretion to determine which

persons to arrest and which places to search. Ibid. The

Fifth Circuit drew a parallel to the first step of

Google’s geofence response protocol, which is to search

the entire Google database—all 592 million individual

accounts—for users who were at a particular location

at a given moment, even though law enforcement does

not yet know—and may never know—who they are

looking for. Id. at 836-837. Accordingly, the Fifth

Circuit correctly held that “geofence warrants fail at

Step-1—they allow law enforcement to rummage

through troves of location data from hundreds of

millions of Google users without any description of the

particular suspect or suspects to be found.” Id. at 837838.

By contrast, the Texas Court of Criminal Appeals

erroneously claimed that probable cause to

retroactively search a person’s location data may exist

if they merely may have witnessed a crime. Pet.19a

(contending that the warrant was framed narrowly

enough to identify a perpetrator or “potentially * * * a

witness.”). In the court’s view, “a witness who might

identify the perpetrators or testify about the offense”

is “not merely an innocent bystander.” Pet.19a. This

Court has consistently emphasized that a person’s

“mere propinquity to others independently suspected

of criminal activity does not, without more, give rise to

probable cause to search that person.” Ybarra v.

Illinois, 444 U.S. 85, 91 (1979) (citing Sibron v. New

York, 392 U.S. 40, 62-63 (1968)). Simply witnessing a

crime does not forfeit the viewer’s Fourth Amendment

rights.

In short, the Founders would have been shocked to

see the privacy protections of the Fourth Amendment

brought to this sorry state. And they doubtless would

have considered such warrants part of that “long train

of abuses” tending to “reduce [the People] under

absolute Despotism.” See Decl. of Independence para.

2 (U.S. 1776). That too is a powerful reason supporting

this Court’s review of the decision below.

CONCLUSION

Geofence

warrants

combine

previously

unimaginable and precise retrospective surveillance

with something akin to a general warrant. This Court

should enforce the Fourth Amendment against

geofence warrants and similar advances in technology

by granting review and then holding that there is a

reasonable expectation of privacy in cell-phone

location data, even for short-term snippets taken from

a long-term compilation.

Respectfully submitted,