Controversial Geofence Warrants Face Supreme Court Challenge
Technological innovations allow the authorities to see who has visited whole geographic areas.
It sometimes seems technology provides a moving target for the Fourth Amendment, evolving new means of snooping on people while courts struggle to keep up. That's the case with Chatrie v. United States, in which the U.S. Supreme Court will soon determine how much leeway the authorities have to electronically search whole geographic areas to discover who was present. Civil liberties groups like the Institute for Justice and the Electronic Frontier Foundation are scrambling to hold the line on search-and-seizure protections in a world where smartphones create a constant record of most people's locations.
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Your Smartphone Reveals Where You've Been
In a January 2026 report on the topic, the Congressional Research Service summarized that "geofence warrants are an investigative tool typically employed when law enforcement knows the approximate time and location of a crime but not the identities of suspects. In executing a geofence warrant, law enforcement compels a company to provide certain information indicating which particular smartphones were present within a geographic area during a specified time frame." Geofence warrants may have most controversially been used to identify people who were present at the January 6, 2021 Capitol riot.
In the current case, Okello Chatrie pleaded guilty to federal charges after the 2019 robbery of the Call Federal Credit Union in Midlothian, Virginia. After the robbery, according to court documents, federal officials obtained a geofence warrant and "directed Google to scan through the private user-controlled accounts of over 500 million Location History users to identify all devices that were, within one hour of a bank robbery, within 150 meters from the scene of the crime." Then, "without obtaining an additional search warrant, law enforcement requested and received names associated with three devices—which included petitioner Okello Chatrie."
Chatrie's legal team challenged the geofence warrant, and the U.S. Court of Appeals for the Fourth Circuit initially ruled that the use of the warrant didn't even constitute a search. Subsequently, a review by the full court resulted in legal indecision, with nine separate opinions.
By contrast, in 2024, the Fifth Circuit found geofence warrants to be unconstitutional general warrants—nonspecific grants of permission to conduct searches—that are forbidden by the Fourth Amendment.
Civil Liberties Groups Warn of Illegal 'General Warrants'
So, the issue landed in the Supreme Court's lap. That has interested parties making their arguments about technological developments—and resulting legal innovations – that have implications for everybody's privacy.
"Geofence searches allow the government to learn the movements, location, and identity of untold numbers of people. As such, as in Carpenter, they violate users' expectations of privacy in their sensitive location data and thus constitute a Fourth Amendment search," argue the Electronic Frontier Foundation (EFF), the American Civil Liberties Union (ACLU), the ACLU of Virginia, and the Center on Privacy and Technology at Georgetown Law in an amicus brief filed this week with the Supreme Court. "By their very nature, geofence searches cast indiscriminate dragnets that turn innocent bystanders into suspects, causing intrusions on a scale far greater than those held unconstitutional in the physical world."
The Institute for Justice (I.J.) agrees. That organization focuses, in particular, on second and third steps taken by the government to target specific devices and unmask identities after the initial geofence warrant.
"The magistrate evaluated probable cause once, at the time the warrant was issued," I.J. notes in its own amicus brief. "Whatever one's view of whether that showing justified the Step 1 search—the initial geofence query—it is the only probable cause determination that a judicial officer ever made. The warrant's structure ensured that no magistrate would evaluate probable cause for either of the two subsequent searches authorized by the warrant."
The Cato Institute, which also filed an amicus brief this week, concurs that "when conduct results in 'a significant expansion' of a prior search, it 'must be characterized as a separate search'.…The three steps authorized by the geofence warrant amount to three separate and distinct searches, each requiring independent review and approval by a neutral magistrate."
Google No Longer Centrally Stores Location Data
Interestingly, problems created by advancing technology can sometimes be resolved—at least in part—by innovators' refinements. After ending up on the receiving end of geofence warrants, Google changed its policy regarding storage of location data.
"With Google, managing location data is simple thanks to tools like auto-delete and Incognito mode. Today, we're introducing new updates to give you even more control over this important, personal information," the company announced in December 2023. "If you're among the subset of users who have chosen to turn Location History on (it's off by default), soon your Timeline will be saved right on your device—giving you even more control over your data. Just like before, you can delete all or part of your information at any time or disable the setting entirely."
For customers who choose to backup data to cloud storage, Google provided automatic encryption so the company would not have access to sensitive information, including locations. Google also set location data to automatically delete after three months.
In its own filing, the company advised the Supreme Court that "Google now lacks the ability to search for and produce user Location History to law enforcement and Google no longer has the ability to respond to geofence warrants." It also argues, "these searches are invasive and often overbroad."
But Google is one company and, as mentioned above, technological progress creates moving targets. Legal doctrine must keep up with changing capabilities and habits. Now that we're all carrying what are essentially tracking beacons that, almost incidentally, offer the ability to communicate and retrieve data, the courts must decide just how freely the authorities can use the data trail that creates. What they decide now will help determine our search-and-seizure protections as the world continues to change.
Until the court decides—and even afterwards, since legal protections are only as effective as the respect for them exercised by the powers that be—people should keep in mind the vulnerabilities created by modern conveniences. If you don't want to be tracked, leave your electronic devices at home.
