Amicus Curiae Brief — George Anibowei, Petitioner v. Todd Blanche, Attorney General, et al.

No. 26-208

IN THE

Supreme Court of the United States

————

GEORGE ANIBOWEI,

Petitioner,

v.

TODD BLANCHE, ATTORNEY GENERAL, et al.,

Respondents.

————

On Petition for a Writ of Certiorari to the

United States Court of Appeals

for the Fifth Circuit

————

AMICUS CURIAE BRIEF OF THE TEXAS

CRIMINAL DEFENSE LAWYERS ASSOCIATION

IN SUPPORT OF THE PETITIONER

————

KYLE THERRIAN

ROSENTHAL, KALABUS &

THERRIAN

7200 State Highway 121

Ste 400

McKinney, Texas 75070

(972) 369-0577

kyle@texasdefensefirm.com

CLAY STEADMAN

President, TCDLA

LAW OFFICES OF JESKO &

STEADMAN

612 Earl Garrett

Kerrville, Texas 78028

(830) 257-5005

jaskoandsteadman@

hotmail.com

AARON M. DIAZ

ST. MARY’S UNIVERSITY

SCHOOL OF LAW

2507 NW 36th Street

San Antonio, Texas 78228

(210) 436-3840

adiaz39@stmarytx.edu

LANE D. THIBODEAUX

Counsel of Record

BRAZOS COUNTY PUBLIC

DEFENDER’S OFFICE

200 South Texas Avenue

Ste. 126

Bryan, TX 77803

(979) 361-4581

LThibodeaux@

brazoscountytx.gov

SARAH DURHAM

BLIZZARD & ZIMMERMAN, P.L.L.C.

1174 North 3rd Street

Abilene, Texas 79601

(325) 230-2751

sarah@blizzardlawfirm.com

WILSON-EPES PRINTING CO., INC. – (202) 789-0096 – WASHINGTON, D.C. 20002

TABLE OF CONTENTS

Page

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

ii

INTEREST OF THE AMICUS CURIAE ............

1

SUMMARY OF THE ARGUMENT ....................

2

ARGUMENT ........................................................

6

I. Digital devices should be subject to 4th

Amendment protection at international

gateways ....................................................

8

A. The reasons for the border search

exception do not extend to cellular

digital devices ......................................

8

B. This case is the next logical question

after Chatrie v. United States, the

most recent in a line of cases

confirming a cell phone’s cultural

ubiquity and private 4th Amendment

status ...................................................

12

II. CBP and ICE policies violate the 4th

Amendment, but the requested shift in

border exception jurisprudence would

directly impact those policies and

ultimately remedy the violation ...............

16

CONCLUSION ....................................................

20

PRAYER...............................................................

21

(i)

ii

TABLE OF AUTHORITIES

CASES

Page(s)

Arizona v. Gant,

556 U.S. 332 (2009) ................................... 10, 11

Boyd v. United States,

116 U.S. 616 (1886) ...................................

6, 8

Carpenter v. United States,

585 U.S. 296 (2018) ................... 2, 12, 13, 15, 16

Chatrie v. United States,

No. 25-112, 609 U.S. --,

2026 W.L. 1855568 (June 29, 2026) ..... 2, 14, 15

Dunaway v. New York,

442 U.S. 200 (1979) ...................................

19

Michigan v. Summers,

452 U.S. 692 (1981) ...................................

19

New York v. Belton,

453 U.S. 454 (1981) ...................................

11

Northwest Airlines, Inc. v. Minnesota,

322 U.S. 292 (1944) ...................................

16

Riley v. California,

573 U.S. 373 (2014) ......................... 2-4, 6, 10, 19

United States v. Aigbekaen,

943 F.3d 713 (4th Cir. 2019) .....................

7, 8

United States v. Cano,

934 F.3d 1002 (9th Cir. 2019) ...................

7

United States v. Flores-Montano,

541 U.S. 149 (2004) ................................... 7, 10

United States v. Jones,

565 U.S. 400 (2012) ...................................

13

iii

TABLE OF AUTHORITIES—Continued

Page(s)

United States v. Knotts,

460 U.S. 276 (1983) ...................................

13

United States v. Kolsuz,

890 F.3d 133 (4th Cir. 2018) .....................

7

United States v. Montoya de Hernandez,

473 U.S. 531 (1985) ................................. 8, 9, 10

United States v. Ramsey,

431 U.S. 606 (1977) ................................. 8, 9, 10

United States v. Touset,

890 F.3d 1227 (11th Cir. 2018) ................... 7, 10

United States v. Vergara,

884 F.3d 1309 (11th Cir. 2018) .................

7

STATUTES AND CONSTITUTIONAL PROVISIONS

Act of July 31, 1789, ch. 5, 1 Stat. 29,

repealed by Act of Aug. 4, 1790, ch. 35,

§73, 2 Stat. 177 .........................................

8

OTHER AUTHORITIES

Alayo-Matos, Daniel Vincente, Extraction,

Retention, and Use: Applying the UseRestrictions to Fourth Amendment

Forensic Electronic Device Search

Doctrine at the Border, 2024 U. Chi.

Legal F. 337 (2025) ...................................

6

Donohue, Laura K., Customs, Immigration,

and Rights: Constitutional Limits on

Electronic Border Searches, 128 Yale

L.J.F.961 (2019) ........................................ 16-18

iv

TABLE OF AUTHORITIES—Continued

Page(s)

https://www.apple.com/iphone/ (last visited

July 2, 2026) ..............................................

3

https://www.cbp.gov/newsroom/stats/south

west-land-border-encounters (last visited

August 31, 2026) .......................................

5

https://internxt.com (last visited July 7,

2026) ..........................................................

3

https://lexarenterprise.com/ (last visited

July 7, 2026) ..............................................

3

Robert, Amanda, Privacy rights of lawyers

and their clients should be protected

during border searches, ABA House

urges, A.B.A. J. (Jan. 2019) ......................

12

U.S. Customs & Border Protection, Border

Search of Electronic Devices at Ports of

Entry, https://www.cbp.gov/travel/cbp-se

arch-authority/border-search-electronicdevices (last visited July 7, 2026)....... 17, 19, 20

U.S. Customs & Border Prot., U.S. Dep’t of

Homeland Sec., CBP Directive No. 3340049B, Border Search of Electronic

Devices (January 1, 2026) ................ 7, 10, 16-18

U.S. Customs and Border Prot., Texas’

Ports of Entry (2024), https://gov.texas.

gov/business (last visited July 7, 2026)....

4

U.S. Immigration & Customs Enforcement,

Directive No. 7-6.1, Border Searches of

Electronic Devices (August 18, 2009) .......

17

v

TABLE OF AUTHORITIES—Continued

Page(s)

World’s Busiest Airports Show Surge in

International Travel. Here are the

Rankings (CNBC, originally aired April

15, 2024). ...................................................

6

INTEREST OF THE AMICUS CURIAE1

The Texas Criminal Defense Lawyers Association

(“TCDLA”) is a non-profit, voluntary membership

organization dedicated to protecting individuals’

rights guaranteed by the state and federal constitutions and to the continuous improvement of the

administration of criminal justice in the State of

Texas.

Founded in 1971, the TCDLA currently has a

membership of over 3,800 and offers a statewide forum

for criminal defense counsel, provides a voice in the

state legislative process in support of procedural

fairness in criminal defense and forfeiture cases, and

assists the courts by acting as Amicus Curiae.

Neither the TCDLA nor any of the attorneys

representing TCDLA have received any fee or other

compensation for preparing this brief, which complies

with all applicable provisions of the Supreme Court

Rules, and copies have been served on all parties.

1

Counsel of record for TCDLA authored this brief in part. No

counsel for a party to this matter participated in drafting. Rule

37.6. No counsel or party made a monetary contribution intended

to fund the preparation or submission of this brief. Id. The

TCDLA timely notified counsel of record of its intent to file an

amicus curiae brief at least ten days prior to its due date

pursuant to Rule 37.2(a) of the Rules of the Supreme Court of the

United States.

2

SUMMARY OF THE ARGUMENT

In 2014, this Court decided that digital data stored

in cell phones, at least in the context of a warrantless

search incident to arrest, was protected by the Fourth

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

Four years later, this Court expanded its reasoning in

Riley to include historical cell site location information

(“CSLI”) – which is arguably less private than stored

data – and held that it, too, was protected by the

Fourth Amendment and not subject to the third-party

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

(2018).

This Court continued its adherence to well-settled

Fourth Amendment principles during the 2025 term,

citing Riley and Carpenter, in Chatrie v. United States,

146 S. Ct. 2193 (2026). Chatrie was a step beyond

Carpenter, holding that a Fourth Amendment search

occurs when police obtain CSLI data from a thirdparty provider for a so-called geofence warrant. Id. at

*4. In doing so, this Court held that individual privacy

interests in phone location data constitute a constitutionally significant intrusion, even if that data is

collected for a limited time. Id.

From Riley to Carpenter to now Chatrie, this Court

has continually recognized the indispensability of

cellular devices among millions. They have become

“such a pervasive and insistent part of daily life that

the proverbial visitor from Mars might conclude they

were an important feature of human anatomy.” Id.

(quoting Riley v. California, 573 U.S. 373, 385 (2014)).

That indispensability is born of convenience and

necessity. Cell phone owners now carry a massive

trove of information in these pocket-sized computers.

3

To that point, Riley emphasized the quantitative

implications of devices with only 16 to 64 gigabytes of

memory, observing that 16 gigabytes translated, in

practical terms, to “millions of pages of text, thousands

of pictures, or hundreds of videos.” Riley, 573 U.S. at

394. The quantitative implications of Riley have grown

exponentially in the dozen years since it was decided.

Cellular devices now offer storage ranging from 256

gigabytes to 2 terabytes. https://www.apple.com/

iphone/ (last visited July 2, 2026). To put that into

perspective, 2 terabytes, which the iPhone 17 Max and

Samsung Galaxy S24 Ultra can hold, amounts to

roughly 200,000 photos, 500,000 songs, hundreds of

hours of 4K video, or millions of pages of documents—

more than enough for typical users. https://inter

nxt.com (last visited July 7, 2026); https://lexarent

erprise.com/ (last visited July 7, 2026).

Cellular digital data privacy concerns exist because

of the “immense storage capacity” of these now

ubiquitous devices and the “element of pervasiveness

that characterizes cell phones but not physical

records.” Riley, 573 U.S. at 375. This Court has

observed that the information in cell phones, like

browsing history, past location data, mapping, calendars, or installed software, is “qualitatively different”

from physical evidence because it implicates “detailed

information about all aspects of a person’s life.” Id.

These considerations apply as strongly to digital,

individual folders and files as they do to the separate

cell phone functions for communications, photo storage, and calendars. Thus, Riley rejected analogy to

physical containers, deciding instead that “modern cell

phones, as a category, implicate privacy concerns far

beyond those implicated by the search of a cigarette

pack, a wallet, or a purse.” Riley, 573 U.S. at 393.

4

Saying physical and digital searches are materially

indistinguishable is “like saying a ride on horseback is

materially indistinguishable from a flight to the

moon.” Id.

Consequently, there is a need to finally address the

now-universal use of cellular devices and warrantless

authority for border searches. Amici is an organization

of criminal defense lawyers in the United States’

second-largest state by area, with the longest international border and 32 ports of entry—more than any

other single state.

U.S. Customs and Border Prot., Texas’ Ports of Entry

(2024), https://gov.texas.gov/business (last visited July

7, 2026).

5

Millions travel through Texas ports each year,

whether by land, air, or sea. https://cbp.gov/news

room/stats/southwest-land-border-encounters

(last

visited August 31, 2026). The existing circuit split

requires reconciling this technology with the border

search exception to the Fourth Amendment. In the 5th

Circuit, these millions include Petitioner, a United

States citizen and licensed Texas attorney who travels

internationally in the course of his business. All

individuals, just by virtue of being at a border entry

point, are subject to a warrantless search of their

cellular devices, at least if their international gateway

is within the 5th Circuit Court of Appeals. These

digital device searches, both manual and the significantly more intrusive forensic searches, are conducted by the Department of Homeland Security

(“DHS”) and its law enforcement agencies, the United

States Customs and Border Protection (“CBP”) and

the United States Immigration and Customs Enforcement (“ICE”) (“border agents”).

Yet in California, Washington, Virginia, and Maryland, or any other state or territory in the 4th and 9th

Circuits, an identical person or citizen would be

afforded Fourth Amendment protection from border

agents. This circuit split, embedded in CBP’s policy

directives, exists between the 9th and 4th Circuit

Courts of Appeals and the 1st, 5th, 8th, 10th, and 11th

Circuit Courts of Appeals, and cannot remain

unaddressed. The reasons for the border search

exception to the warrants clause of the Fourth

Amendment, as argued in Section IA, and this Court’s

recognition of the changing nature of cellular devices

favor the approaches taken by the 9th and 4th

Circuits.

6

ARGUMENT

Modern cell phones are not just another technological convenience. With all they contain

and all they may reveal, they hold for many

Americans ‘the privacies of life.’

Riley v. California, 573 U.S. 373, 403 (2014) (quoting

Boyd v. United States, 116 U.S. 616, 625 (1886)).

The Dallas-Fort Worth International Airport

(“DFW”) is the eighth-busiest international gateway in

the United States. World’s Busiest Airports Show

Surge in International Travel. Here are the Rankings

(CNBC, originally aired April 15, 2024). Petitioner is

one of many Texas-licensed attorneys who use not just

DFW, but also George Bush Intercontinental Airport

in Houston for international travel. American business travelers like Petitioner are also not the sole

users of these Texas gateways. Non-business travel

along the 833-mile stretch from El Paso to Brownsville

includes international gateways in Del Rio, Eagle

Pass, and Laredo.

A recent University of Chicago Legal Forum

Comment cited 2024 statistics that CBP “still

annually processes 40,0000 travelers, along with their

electronic devices, with limited suspicion and few

judicial limits on use of the harvested data.” Daniel

Vincente Alayo-Matos, Extraction, Retention, and Use:

Applying the Use-Restrictions to Fourth Amendment

Forensic Electronic Device Search Doctrine at the

Border, 2024 U. Chi. Legal F. 337, 339 n. 10 (2025).

The 2024 statistics haven’t improved much. The

CBP’s most recent iteration of its Directive, published

in January 2026, purports to require some level of

suspicion for more intrusive forensic inspections and

seems consistent with this Court’s past recognition of

7

self-imposed agency restrictions for determining reasonableness under the Fourth Amendment. See United

States v. Flores-Montano, 541 U.S. 149, 156 (2004)

(Breyer, J. concurring); see also CBP Directive §§ 5.1.3

and 5.1.4. However, confusion remains when attempting to reconcile these directives and the different

circuit requirements, or lack thereof.

The 11th Circuit has held that no threshold level is

required to seize and search cellular devices. United

States v. Touset, 890 F.3d 1227, 1232-33 (11th Cir.

2018). Touset held that a reasonable suspicion was

unnecessary even for a forensic search of a cellular

device. Touset followed the 11th Circuit’s holding in

United States v. Vergara that the Fourth Amendment’s Warrant Clause was inapplicable to such

device searches. See United States v. Vergara, 884

F.3d. 1309, 1311 (11th Cir. 2018).

At the other end of the spectrum is the 9th Circuit

Court of Appeals, which has the narrowest view of the

border search exception. United States v. Cano, 934

F.3d 1002 (9th Cir. 2019). In Cano, the Court held that

border agents may use the exception only to stop

contraband from entering the United States. Id. at

1013. According to the 9th Circuit, the “detection of

[contraband] is the strongest historic rationale for the

border-search exception,” and the search of devices

such as cellular phones does not fit that rationale

except for child pornography. Id. at 1021 n.13.

The 4th Circuit Court of Appeals’ view of the border

exception and cellular devices is slightly broader: a

forensic search of a cellular device in that Circuit is

nonroutine under the border search exception and

requires individualized suspicion. See United States v.

Kolsuz, 890 F.3d 133, 144 (4th Cir. 2018). A year later,

in United States v. Aigbekaen, the 4th Circuit went a

8

step further in its own precedent and moved closer to

the 9th Circuit’s, holding that a nexus must exist

between an intrusive forensic search of a cellular

device and the purpose undergirding the border

exception. See United States v. Aigbekaen, 943 F.3d

713 (4th Cir. 2019).

For those millions of international travelers who use

cellular devices, the combined logic of the 9th Circuit’s

Cano and 4th Circuit’s Aigbekaen; coupled with this

Court’s holdings in Riley and Carpenter, hits closer to

the mark of how electronic devices should be treated

at the border than the 11th Circuit’s in Vergara and

Touset.

I. Digital devices should be subject to 4th

Amendment protection at international

gateways

A. The reasons for the border search

exception do not extend to cellular

digital devices

When crossing any international border to or from

the United States, an individual implicitly agrees to

an inspection—history and tradition acknowledged

from the late 18th century to the present day. See Act

of July 31, 1789, ch. 5, 1 Stat. 29, repealed by Act of

Aug. 4, 1790, ch. 35, §73, 2 Stat. 177 (“The 1789

customs statute”); Boyd v. United States, 116 U.S. 616,

623 (1886). The border search exception to the Fourth

Amendment’s warrant requirement is often tied to the

government’s legitimate interest in protecting the

integrity of the nation’s borders. United States v.

Ramsey, 431 U.S. 606, 616 (1977); but see United

States v. Montoya de Hernandez, 473 U.S. 531, 544

(1985) (communicating the reason as the government’s

high interest in preventing anything harmful from

9

entering, such as “communicable diseases, narcotics,

or explosives”).

Ramsey highlights that port-of-entry inspection was

not without limitation, even at the founding. Ramsey

used the 1789 customs statute to support the history

and tradition of such limitation. Section 24 of that

statute provided, in pertinent part:

[E]very collector, naval officer and surveyor,

or other person specially appointed by either

of them for that purpose, shall have full power

and authority, to enter any ship or vessel, in

which they shall have reason to suspect any

goods, wares or merchandise subject to duty

shall be concealed; and therein to search for,

seize, and secure any such goods, wares or

merchandise; and if they shall have cause to

suspect a concealment thereof, in any particular dwelling-house, store, building, or other

place, they or either of them shall, upon

application on oath or affirmation to any

justice of the peace, be entitled to a warrant

to enter such house, store, or other place (in

the day time only) and there to search for

such goods, and if any shall be found, to seize

and secure the same for trial. . . .

Ramsey, 431 U.S. at 616 n.12 (1977) (emphasis added).

Ramsey recognized that seizure was tethered to a

search limitation: “Here envelopes are opened at the

border only when customs officers have reason to

believe they contain something other than correspondence. Reading the correspondence inside the

envelopes was forbidden.” Id. at 624. The Court also

recognized that, under some circumstances, a border

search might be unreasonable: “We do not decide

10

whether, and under what circumstances, a border

search might be deemed ‘unreasonable’ because of the

particularly offensive manner in which it is carried

out.” Id. at n.13. (citations omitted). Analysis has tied

heightened scrutiny to general rummaging, as in the

forbidden letter-reading from Ramsey. No leap is

required from letter to smartphone. The invasion

cascades into reading, downloading, and collating

terabytes of personal, protected, and professional data

stored on these devices.

A “routine” search of an individual is “not subject to

any requirement of reasonable suspicion, probable

cause, or warrant.” United States v. Flores-Montano,

541 U.S. 149, 153 (2004) (citing Montoya de

Hernandez, 473 U.S. at 538); see CBP Directive 5.1.2.

These nonroutine searches of persons are subject to a

higher individualized “reasonable suspicion” standard. Id.; see also Touset, 890 F.3d at 1234; see also CBP

Directive 5.1.3. In other words, a border agent may

conduct an intrusive, nonroutine search of a person

only if the agent has reasonable suspicion that the

individual is engaging in an activity the exception is

intended to prevent.

A search becomes nonroutine when it goes “beyond

the scope of a routine customs search and inspection”

Montoya de Hernandez at 541. For example, “strip,

body cavity, or involuntary x-ray searches.” Id. at n.4.

The Supreme Court in Riley held that forensic

searches of cell phone data are also highly intrusive,

nonroutine searches because the “sum of an individual’s private life can be reconstructed” with the

device’s stored data. Riley, 573 U.S. at 394.

With these decisions from this Court, the reasons for

the Fourth Amendment exception “define the boundaries of the exception.” See Arizona v. Gant, 556 U.S.

11

332, 339 (2009). This means, in the context of the

Question Presented by Petitioner, this Court uses the

Fourth Amendment’s long-standing test of balancing

the Government’s interest against the individual’s

personal expectation of privacy.

Gant illustrates this point. In Gant, the searchincident-to-arrest exception was narrowed after New

York v. Belton, 453 U.S. 454 (1981), which many law

enforcement agencies had implemented.2 Gant held

that the search incident to arrest exception did not

justify the search there challenged because (1) the

police could not reasonably have believed that the

arrestee could have accessed the car at the time of the

search; and (2) police could not have reasonably

believed that the evidence of the offense for which the

arrestee was arrested might have been found in the

car since the arrest was for driving with a suspended

license. 556 U.S. at 344.

Gant recognized that the purpose of the search

incident to arrest exception was different, and officer

safety concerns were diminished because the defendant was secured during the search and the arrest was

unconnected to a search of personal items inside the

vehicle. Id. at 344-46. In sum, Gant declined to extend

the search-incident-to-arrest exception because the

situation was too attenuated from the exception’s

2

The Supreme Court wrote, “Countless individuals guilty of

nothing more serious than a traffic violation have had their

constitutional right to the security of their private effects violated

as a [result of law enforcement’s reading of Belton]. The fact that

the law enforcement community may view the State’s version of

the Belton rule as an entitlement does not establish the sort of

reliance interest that could outweigh the countervailing interest

that all individuals share in having their constitutional rights

fully protected.” Gant, 556 U.S. at 349.

12

purpose. Riley then extended the Gant reasoning to

cell phones by not extending the search incident to

arrest exception to cell phones.

This Court has already lifted cell phones out of the

ambit of the search incident to arrest exception; the

leap to the border search exception is not a long one.

Indeed, the Government interests of prohibiting

contraband or unwanted individuals from entering

this country are served when border agents search

luggage or a person’s pockets at a border crossing, and

the border search exception has substantial justifycation when screening entrants bringing harm or

harmful products into the country, be it communicable

diseases, narcotics, or explosives.

But when weighed against the millions and millions

of travelers with digital devices – especially those like

Petitioner – the governmental interests the border

search exception was designed to protect are dwarfed,

and any warrantless search, whether manual or

forensic, is incredibly invasive.3

B. This case is the next logical question after

Chatrie v. United States, the most recent in

a line of cases confirming a cell phone’s

cultural ubiquity and private 4th Amendment status

Technological advancement demands greater, not

less, 4th Amendment protection. In Carpenter, the

Court traced how technological advancement increasees an individual’s privacy rights and simultaneously

3

Amanda Robert, Privacy rights of lawyers and their clients

should be protected during border searches, ABA House urges,

A.B.A. J. (Jan. 2019) (addressing concerns over breaches of

attorney client privilege during border searches).

13

decreases the Government’s ability to permeate them.

Carpenter, 585 U.S. at 304-09.

The Court explained the correlation in its discussion

of two lines of cases intersected by Carpenter. The first

line included the Government’s monitoring of private

citizens in 1983 versus 2012 in Knotts and Jones. In

Knotts, the Court determined that the Government’s

placement of a tracking beeper during one “discrete

automotive journey” of a co-conspirator was rudimentary in nature and did not violate his 4th

Amendment rights. Id. at 306 (quoting United States

v. Knotts, 460 U.S. 276, 284-85 (1983)). The Court

reserved the question of whether “different constitutional principles may be applicable” if “twenty-fourhour surveillance of any citizen of this country [were]

possible.” Id. at 306-07 (quoting Knotts 460 U.S. at

283-84). So, in 1983, the Court considered that

technological advancement allowing 24-hour surveillance of a citizen would change the 4th Amendment

calculus. And it did.

Following 30 years of advancing technology, FBI

agents in Jones placed a GPS tracking device on

Jones’s vehicle. They remotely monitored it for 28

days—a far cry from following a beeper in a box of

chloroform for the duration of a drive. See Knotts, 460

U.S. 276, 278. While the Court’s 2012 decision in Jones

was not grounded in the 4th Amendment, it discussed

the predicted technological advancement of 24-hour

monitoring. Carpenter at 307. The concurring Justices

noted that GPS monitoring would infringe on one’s

expectation of privacy because it monitors “every

movement” a person makes. Id. (citing United States

v. Jones, 565 U.S. 400, 430 (2012) (Alito, J. concurring)).

14

Cell phone location data, similar to, but technologically beyond, the GPS monitoring in Jones, records

“every movement” a person makes. A cell phone travels with its human, and since Carpenter, cell phone

applications have grown increasingly granular as to

the information they record and store. Whether

through Life 360, Snapchat, a favorite running app, or

any variety of other location-tracking apps, the search

of one’s cell phone won’t just reveal where the car

drove or where the bus stopped. Contemporary cell

phone applications reveal minutiae of movement—

tracking whether the individual in possession of the

device is on the 1st or 5th floor of a building, or even

how high their heart rate rose when climbing the

stairs to reach the 5th floor. Every movement.

Chatrie arguably went further than Carpenter in

recognizing that Fourth Amendment exceptions and

the constitutional baseline of “reasonableness” must

now be considered in light of smartphone device

technology. The majority opinion, citing Carpenter,

rejected compartmentalization of these devices for

Fourth Amendment protections:

Consider sending an email on Gmail, uploading a photo to Google Photos, or adding a

calendar entry to Google Calendar. None happens solely by dint of the phone’s operation;

each requires, as Location History does, an

“optional add-on.” Brief for United States 13.

And each activity, like using Location History, results in sharing information with a

third-party tech company—turning over private materials to live on that company’s

servers. The Government wishes to disconnect all those uses from the mere act of

carrying a turned-on cell phone (the thing

15

that generates CSLI), with only the latter

receiving assured Fourth Amendment protection. But that is to imagine that all of us are

living in dumb flip-phone days. The point of

carrying smartphones is to use what is on

them—as Carpenter said, to use the apps and

“services they provide.” That is what has

become a “pervasive and insistent”—even

“indispensable”—”part of daily life.” And

so that is what Carpenter insulated from the

third-party doctrine. A cell-phone user is not

to be viewed as sharing private information

with third parties—which then can be freely

passed on to the government—just by doing

the ordinary things cell-phone users do.

Chatrie, 146 S. Ct. at 2214 (citations omitted)

(emphasis in the original).

From Riley to Carpenter to now Chatrie, this Court

has for a dozen years recognized that certain warrantless searches of digital data stored on a cellular

device, smartphone, or by a third party are unreasonable under the Fourth Amendment. This case

presents a question with practical and legal urgency

for the millions who travel internationally each year

with their digital devices—should a 4th Amendment

violation be excused by mere virtue of where it occurs?

The answer must be no. The privacy implications of

technology’s exponential advancement will only increase as time wears on. And this question will be posed

again and again. Now is the perfect time to answer it

in favor of the 4th and 9th Circuits and the Fourth

Amendment protection afforded to all Americans.

When considering new innovations in airplanes and

radios, Carpenter quoted Justice Felix Frankfurter,

“the Court must tread carefully in such cases, to

16

ensure that [it does] not ‘embarrass the future.’ ”

Carpenter at 316 (quoting Northwest Airlines, Inc. v.

Minnesota, 322 U.S. 292, 300 (1944)).

II. CBP and ICE policies violate the 4th

Amendment, but the requested shift in

border exception jurisprudence would

directly impact those policies and

ultimately remedy the violation

As described above, the border-search exception to

the Fourth Amendment’s warrant requirement has

been around for a long time. But the original impetus

for Congress’ grant of such authority to the Executive

has been stretched over the past century to include

permissions to law enforcement not originally intended. In the late 19th and early 20th centuries, only

two justifications existed for broad border search

authorities: (1) “to regulate the collection of duties and

to prevent the introduction of contraband into this

county;” and (2) to determine who should be admitted

to the United States. Laura K. Donohue, Customs,

Immigration, and Rights: Constitutional Limits on

Electronic Border Searches, 128 Yale L.J.F.961, 96263 (2019). While DHS agencies, CBP and ICE, exist to

effectuate those purposes, both now operate in ways

that exceed their original grant of authority to the

point of violating the 4th Amendment.

Both agencies publish directives specific to electronic device searches at the border. CBP’s latest

directive, No. 3340-049B (“CBP Directive”) was

updated and became effective on January 1, 2026. U.S.

Customs & Border Prot., U.S. Dep’t of Homeland Sec.,

CBP Directive No. 3340-049B, Border Search of

Electronic Devices (January 1, 2026). In it, CBP

outlines what kind of searches its officers can perform

on electronic devices; how individuals’ rights are

17

consequently affected; and details specifics concerning

what CBP can retain from a searched device and for

how long. ICE’s parallel document has not been

updated since 2009 but is referenced in CBP’s

Directive. Id. at 2, §2.8 (citing U.S. Immigration &

Customs Enforcement, Directive No. 7-6.1, Border

Searches of Electronic Devices (August 18, 2009)).

The CBP Directive states that it “conducts border

searches in accordance with applicable statutes,

regulations, and judicial authorities.” CBP Directive

§ 2.9. Relevant to Petitioner’s position here, the same

section explains that “[a]dditional or different requirements may apply in certain jurisdictions to ensure

compliance with binding circuit precedent—that [t]he

location where the border search is initiated determines which policy guidance applies.” Id. The CBP

acknowledges the Circuit split that exists on this issue

and already adjusts its approach based on where a

particular search is taking place. Even so, the adjusted

approach spurred by the Circuit split has not yielded

a search slowdown.

The last decade has instead seen a steady increase

in the number of electronic device border searches

performed by CBP and ICE. In 2015, CBP examined

8,503 devices, and that number exploded to more than

30,000 in 2017. Donohue, supra at 962-963. In 2024,

that number grew to 46,958. U.S. Customs & Border

Protection, Border Search of Electronic Devices at

Ports of Entry, https://www.cbp.gov/travel/cbp-searchauthority/border-search-electronic-devices (last visited July 7, 2026). In 2025, it increased to 55,424. Id. So

far, 2026 promises to surpass 2025 as the first two

quarters yielded 32,349 searches of electronic devices.

Id.

18

As for ICE, in 2015, it searched almost 5,000 electronic devices. In 2016, that number more than

quadrupled to 23,000 electronic device searches.

Donohue, supra at 962. No additional statistics

pertaining solely to ICE are available online. ICE does

not publish electronic device search statistics on its

website like the CBP, but it stands to reason that in

the last 10 years since ICE’s quadrupled 23,000

searches in 2016, its number of searches has grown

along with CBP’s.

The CBP Directive notes that the “courts have

rejected a categorical exception to the border search

doctrine for electronic devices.” While that statement

is true, it requires qualification. Thus far, this Court

has rejected a categorical exception to the border

search doctrine for electronic devices, but the 4th and

9th Circuits have not. The courts are divided on this

issue.

Should the Court’s analysis and conclusion square

with the 4th and 9th Circuits to implement a

categorical exception for electronic device searches at

the border, at least the CBP’s Directive suggests that

it would recognize and nimbly acquiesce to such

judicial authority. See CBP Directive §§ 2.9 and 4.5.

As it stands, CBP’s Directive purports that its

electronic device search policy “imposes certain

requirements, above and beyond prevailing constitutional and legal requirements to ensure that the

authority for border search of electronic devices is

exercised judiciously, responsibly, and consistent with

the public trust.” Id. at § 4.5.

And that sounds good. But Petitioner’s present case

suggests that, in practice, CBP’s Directive is not as

“above and beyond prevailing constitutional and legal

19

requirements” as advertised. Over the course of several years, and four times while Petitioner’s lawsuit was

pending, his cell phone was confiscated and searched

at the border as he passed through Texas airports. It

became such a problem that Petitioner stopped taking

his cell phone with him when he traveled.

The Court pointed out in Riley that “the Founders

did not fight a revolution to gain the right to government agency protocols.” Riley, 573 U.S. at 398. That

point is well taken here. The Riley Court further

underscored its “general preference to provide clear

guidance to law enforcement through categorical

rules, quoting its Summers decision: “[I]f police are to

have workable rules, the balancing of the competing

interests… ‘must in large part be done on a categorical

basis—not in an ad hoc, case-by-case fashion by

individual police officers.’ Id. (quoting Michigan v.

Summers, 452 U.S. 692, 705 n. 19 (1981) quoting

Dunaway v. New York, 442 U.S. 200, 219-20 (1979)

(White, J. concurring)). The balancing of competing

interests here—safety and privacy—should not be

decided on a case by case or Circuit by Circuit basis. A

categorical exception to border searches for cell phones

would create certainty for federal agencies and

citizens and have an immediate and practical impact

on millions of lives.

In 2025, CBP alone processed 419 million travelers

at United States’ ports of entry, and as mentioned

above, performed 55,318 electronic device searches in

2025. On its website, CBP appears to minimize the

action, stating “CBP only searched the electronic

devices of 55,318 international travelers.” Certainly,

55,318 represents .01% of all international travelers

arriving in 2025. U.S. Customs & Border Protection,

Border Search of Electronic Devices at Ports of Entry,

20

https://www.cbp.gov/travel/cbp-search-authority/bord

er-search-electronic-devices (last visited July 7, 2026).

But that brand of relativity has no bearing on

Petitioner’s case. He may be but one of the millions

traveling through ports of entry and but one of the

thousands whose electronic devices were searched.

But his is not the only phone to be searched without a

warrant, without probable cause, or without reasonable suspicion. Rather, Petitioner’s case is a clarion

call for the Court to solve the split in favor of the 4th

and 9th Circuits and extend its electronic devicerelated jurisprudence to categorically remove those

devices from the border search exception.

CONCLUSION

The question presented is ripe for decision. The

growing recognition of the need for privacy in smartphones and cellular technology must be reconciled

with governmental interests at border crossings. This

is most acute in a situation occasioned by Petitioner,

an individual with not just a privacy interest in his

digital device but with a professional responsibility for

confidentiality. Fourth Amendment protections are

reasonable in the context of this technology, regardless

of whether it is a search incident to arrest, as in Riley,

or a search at an international gateway.

21

PRAYER

For the foregoing reasons, Amicus supports the

Petitioner’s request that the judgment of the 5th

Circuit Court of Appeals be vacated, and the case

remanded for further proceedings.

Respectfully submitted,

KYLE THERRIAN

ROSENTHAL, KALABUS &

THERRIAN

7200 State Highway 121

Ste 400

McKinney, Texas 75070

(972) 369-0577

kyle@texasdefensefirm.com

CLAY STEADMAN

President, TCDLA

LAW OFFICES OF JESKO &

STEADMAN

612 Earl Garrett

Kerrville, Texas 78028

(830) 257-5005

jaskoandsteadman@

hotmail.com

AARON M. DIAZ

ST. MARY’S UNIVERSITY

SCHOOL OF LAW

2507 NW 36th Street

San Antonio, Texas 78228

(210) 436-3840

adiaz39@stmarytx.edu

LANE D. THIBODEAUX

Counsel of Record

BRAZOS COUNTY PUBLIC

DEFENDER’S OFFICE

200 South Texas Avenue

Ste. 126

Bryan, TX 77803

(979) 361-4581

LThibodeaux@

brazoscountytx.gov

SARAH DURHAM

BLIZZARD & ZIMMERMAN, P.L.L.C.

1174 North 3rd Street

Abilene, Texas 79601

(325) 230-2751

sarah@blizzardlawfirm.com