The Supreme Court’s ruling in Chatrie v. United States marks a decisive shift in the law governing modern digital surveillance, holding that government acquisition of stored location history constitutes a Fourth Amendment search and rejecting the argument that users surrender their privacy rights simply by enabling routine device features.
The Digital Dragnet: Warrants on Aggregated Data
Cell phones are everywhere today. From location history stored by Google to search terms logged by providers, everyday mobile devices generate vast amounts of digital data. While these records provide law enforcement with powerful investigative tools, methods known as reverse warrants raise serious constitutional concerns. Instead of starting with a known suspect, investigators require tech companies to search their databases for anyone present in a specific location or searching specific terms, analyzing data from many users to identify potential suspects.
A fundamental question courts have grappled with is whether these digital “dragnets” satisfy the Fourth Amendment’s requirements of probable cause and particularity, or if they are a modern iteration of the unconstitutional general warrants the Framers sought to prohibit. Courts have struggled to adapt Fourth Amendment precedent to the mechanisms of these modern warrants, as shown by the jurisprudential split between the Fourth and Fifth Circuits. However, the most recent Supreme Court decision in Chatrie v. United States marks a shift in this landscape, providing definitive guidance on whether accessing stored location data constitutes a Fourth Amendment search.
Types of Reverse Warrants
Modern law enforcement commonly uses two types of reverse warrants: geofence warrants and keyword warrants. Geofence warrants request data from a technology company for all devices that were physically present within a defined geographical area—the “geofence”—during a certain time frame. The typical process involves multiple steps that require significant coordination between the government and tech companies.
Law enforcement first requests anonymized, time-stamped location data for every device within the designated area. Investigators then use other techniques—and, when necessary, additional data requests—to narrow the list. Finally, they seek identifying details, such as usernames, birth dates, and device information, for the remaining users. This staged process is intended to limit disclosure of personal information before investigators have individualized suspicion. Although geofence warrants can generate leads where none previously existed, their broad scope generates legal controversy.
Like geofence warrants, keyword warrants begin with a broad search of activity and narrow it to specific digital identities, but they target users’ knowledge or intent rather than physical location. Keyword warrants compel search engine providers to disclose the identities of users who searched for specific terms or phrases. These warrants require technology companies to search users’ search histories for specified terms within a defined jurisdiction or time period and provide law enforcement with a list of potential suspects. Because search histories can reveal intimate details about a person’s life, these warrants are controversial for allowing law enforcement to treat expressions of thought as grounds for suspicion. More broadly, reverse warrants remain controversial because they rely on vast data searches to establish individualized suspicion.
The Fourth Amendment Requirements of Probable Cause and Particularity
The text of the Fourth Amendment states the requirements of a warrant, including probable cause and particularity:
The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.
Critics of geofence and keyword warrants claim that they do not satisfy the constitutional requirements of probable cause and particularity. Proponents, on the other hand, claim that these reverse warrants pass constitutional muster.
Probable Cause
Probable cause is a legal standard that law enforcement must meet to obtain a warrant. Defined in Illinois v. Gates, probable cause exists when there is a fair probability that evidence of a crime will be found in a particular place. Critics of reverse warrants point out, as a threshold issue, that these warrants do not identify a particular suspect for the crime because no suspect yet exists. They argue that reverse warrants seek evidence to establish probable cause and identify a suspect, rather than rely on existing probable cause to search a user. Further, critics argue that the warrants rest on an assumption that users in a particular area or who search certain words could be guilty of a crime. Critics argue these assumptions are insufficient for the finding of probable cause.
Proponents, however, argue that probable cause is a flexible standard, sufficiently met in the context of a reverse warrant. They assert that probable cause exists under Gates because police have reason to believe that evidence, such as the identity of the perpetrator, will be found somewhere within the vast data set being requested. Accordingly, proponents argue that probable cause exists when police reasonably expect a search of the company’s servers to uncover necessary evidence. For geofence warrants, that expectation rests on the likelihood that the requested evidence is stored on the recipient company’s servers.
Particularity
The founders understood that a particularity requirement for warrants would combat the evils of historical writs of assistance, which were general warrants used to raid homes and perpetrate unreasonable searches and seizures. The requirement aims to ensure that the warrant is tailored to its justifications. The Fourth Amendment stipulates that a warrant must “particularly describe the place to be searched, and the persons or things to be seized,” prohibiting general searches.
One of the most potent arguments against reverse warrants is that they are the modern equivalent of general warrants, used to search broadly and without specific targets. Critics contend reverse warrants fail the particularity requirement because they compel the search of data belonging to thousands of innocent people simply because they were at the wrong place at the wrong time. They argue that a warrant must instead link the crime to a specific person or place at the time it is issued. The reverse warrant, effectively, is a request to produce a massive digital haystack.
Proponents counter that reverse warrants can be sufficiently particular so long as they are not overly broad. Ideally, the warrants specify the precise geographic coordinates, time frame, and data type to remain within constitutional bounds. The multi-step process used to narrow the data also acts as a necessary restriction on the capture of data to minimize law enforcement discretion in the execution of a warrant. A proposed method of executing reverse warrants in conformance with particularity principles suggests that law enforcement draw multiple relevant geofence boundaries and then search for users found in all boundaries.
The Split in Judicial Authority
This entire legal area is scrutinized under the shadow of the Supreme Court’s landmark ruling in Carpenter v. United States. In Carpenter, the Court addressed whether the government violated the Fourth Amendment by conducting a warrantless search of a person’s historical cell-site information (CSLI). The Court ruled that it did, establishing that a person has a reasonable expectation of privacy in their CSLI due to its comprehensive and aggregated nature. The Court held that the acquisition of such vast, aggregated location data was considered a search under the Fourth Amendment, and therefore, was subject to its warrant standards.
Courts that opposed the use of reverse warrants, such as the Fifth Circuit, viewed these warrants and their searches as a logical extension of the unconstitutional surveillance in Carpenter. These courts argued that geofence warrants are an even more invasive form of the intrusion that the Carpenter majority focused on because they capture the location history of thousands of non-suspects. Conversely, courts that upheld reverse warrants attempted to distinguish them from Carpenter based on the defendant’s voluntary act of sharing data with the technology provider. They argued that a reverse warrant for a small area and brief period of time does not constitute the same kind of “detailed chronicle” of an individual’s life.
The Fifth Circuit’s Take
The Fifth Circuit Court of Appeals rejected the use of geofence warrants in United States v. Smith. In Smith, the court deemed geofence warrants to be “general warrants categorically prohibited by the Fourth Amendment” and ruled them unconstitutional. The Fifth Circuit heavily focused on the fact that the warrant compelled a search for vast amounts of data belonging to non-suspects in coming to its conclusion. The court stated that the “quintessential problem” with geofence warrants is they do not identify a specific user for the search, but only a boundary where any user may appear. Ultimately, the Fifth Circuit ruled that the warrant at issue was unconstitutional because it allowed the same type of rummaging as a general warrant, which the Fourth Amendment was designed to prevent.
The Fourth Circuit’s Take
Sharply contrasting the Fifth Circuit, the Fourth Circuit affirmed the constitutionality of reverse warrants in United States v. Chatrie. In Chatrie, the defendant was convicted of bank robbery using evidence obtained from a geofence warrant. In its opinion, the Fourth Circuit addressed a more fundamental question of whether the government’s access to such data constitutes a Fourth Amendment “search” in the first place. The court held that the government’s conduct did not constitute a search because Chatrie lacked a reasonable expectation of privacy in the limited data collected. Crucially, the court differentiated the data in Chatrie from the data at issue in Carpenter. The court distinguished reverse warrant data from CSLI because Google’s location setting is disabled by default and activated only through an affirmative user choice; it therefore deemed the data voluntarily shared and outside Fourth Amendment protection.
The Supreme Court and Chatrie
Following the Fourth Circuit’s decision, Okello Chatrie petitioned the Supreme Court of the United States to resolve the constitutional issue. On January 16, 2026, the Supreme Court granted certiorari in Chatrie v. United States, marking the first time the Supreme Court has agreed to directly address the constitutionality of geofence warrants. The case drew vast amounts of attention from civil liberties groups, technology giants, and legal scholars, with over 30 amicus curiae briefs filed. The Court granted review on a single fundamental question: whether the execution of the geofence warrant violated the Fourth Amendment.
In its decision, the Supreme Court resolved the threshold question, ruling that government acquisition of location history data from a tech provider constitutes a search under the Fourth Amendment. The Court rejected the lower court’s reliance on the third-party doctrine, clarifying that users do not surrender their reasonable expectation of privacy simply by enabling location settings or using location-aware applications. Drawing directly on Carpenter, the Court emphasized that location history data creates a uniquely intimate record of an individual’s physical movements, making government access to such databases an intrusion that triggers Fourth Amendment protections regardless of whether monitoring spans weeks or merely for a couple of hours.
However, the Court stopped short of declaring all geofence warrants categorically invalid on their face. Instead, the Court remanded the case back to the lower courts to evaluate whether the specific warrant in Chatrie satisfied the Fourth Amendment’s individualized probable cause and particularity requirements, and to address whether law enforcement acted under the good-faith exception to the exclusionary rule.
Looking Ahead
The Supreme Court’s ruling in Chatrie v. United States marks a decisive shift in the law governing modern digital surveillance. By holding that access to stored location history constitutes a Fourth Amendment search, the Court rejected the argument that users surrender their privacy rights by enabling routine device features. The decision leaves lower courts to define how probable cause and particularity apply when law enforcement draws digital boundaries around crime scenes. As policing methods and technology evolve, Chatrie reinforces the Framers’ prohibition on broad, exploratory general warrants in the digital age.
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