The U.S. Supreme Court heard arguments about a relatively new law enforcement technique that lets police ask tech companies to search large swaths of their location data to find who was near a crime scene. The question before the justices: is geofencing an ingenious investigative tool, an Orwellian dragnet, or both — and is it constitutional?
Geofencing lets authorities draw a virtual perimeter around a location and seek a warrant compelling a company to identify any users whose devices were inside that area at a specific time. In the case before the court, the government relied on Google’s Location History, which, on average, records a user’s location every two minutes by combining multiple signals. At the time this investigation began in 2019, roughly one-third of Google users — about 500 million people — had opted into that feature and had their location records stored in Google’s cloud, available to law enforcement with a warrant.
Stanford law professor Orin Kerr called geofence warrants “a little bit of an investigative lottery ticket” when other leads run dry. The constitutional issue centers on the Fourth Amendment’s prohibition on unreasonable searches and seizures and the requirement that warrants be issued by neutral magistrates and aimed at particularized evidence.
Legal scholars note the court has repeatedly grappled with adapting an 18th-century amendment to modern technology. Michael Dreeben, a veteran Supreme Court advocate for the Justice Department, says the court has tended to protect privacy in the digital era to prevent broad, Big Brother-style surveillance. Several recent decisions have recognized that detailed, continuous location tracking from cell phones raises serious privacy concerns.
The case arises from a 2019 bank robbery in Midlothian, Virginia, where $195,000 was stolen. Investigators reviewed surveillance footage showing a man using a cellphone but, after two months, had no suspect. Police obtained a magistrate-issued geofence warrant for an area roughly the size of three football fields around the bank and asked Google for location data from an hour before to an hour after the robbery. Google initially identified 19 devices in the area, then negotiated with police to narrow that list to nine and then three devices it would unmask. One of those identified, Okello Chatrie, was arrested; the other two were apparently innocent bystanders.
Critics warn geofence warrants sweep up many innocent people — commuters, worshippers, medical patients or people visiting partners — and could chill lawful activities like protests or political organizing. Dreeben acknowledges these risks but notes geofencing can also be valuable: investigators used similar techniques after the Jan. 6 Capitol attack to distinguish those who breached the Capitol from those lawfully present.
The government argues users who opted into Google’s Location History waived any reasonable expectation of privacy in those records, and because the defendant did not take steps to shield his location, he has no privacy claim. The defense counters that the warrant was overly broad and akin to the general warrants the Founders opposed — it authorized searching “every single person’s account” for evidence and thus violated the Fourth Amendment’s particularity and reasonableness requirements.
Defense counsel stresses that although the government says it only searched Google, compelling Google to sift through millions of accounts is effectively a dragnet. If placing data in the cloud means giving it away, many records long thought private would become easily searchable by government request. Dreeben frames the question for the court as twofold: whether geofence searches are covered by the Fourth Amendment at all, and whether people who voluntarily store location data with a provider lose any privacy protection for that information. He notes even cloud-based travel diaries or location logs maintained for a user’s benefit should have some protection from arbitrary government action.
How common geofence warrants are is uncertain. A 2020 Hofstra Law Review article reported about 11,500 geofence warrants served on Google that year. The case is likely one of many to test these issues. Google has already adjusted practices, moving some data storage to users’ devices rather than its servers, and filed a brief urging that digital records receive the same protections as physical records and that a warrant requirement apply. Other tech companies may differ in how readily they comply with government requests.
Legal observers say the court’s decision could have broad implications: if the court bars broad geofence warrants or requires stricter particularity, many investigative practices will be constrained; if it allows them, law enforcement will retain a powerful investigative tool but privacy advocates fear expanded surveillance. A ruling is expected by early summer.