Supreme Court rules geofence location searches require a warrant, extending Fourth Amendment to digital tracking data

The U.S. Supreme Court ruled on Monday that law enforcement must obtain a warrant to access historical cellphone location data held by tech companies, a decision that limits the use of so-called geofence warrants across the country. Justice Elena Kagan wrote the majority opinion, joined by Chief Justice John Roberts and Justices Sonia Sotomayor, Brett Kavanaugh, and Ketanji Brown Jackson. Justice Neil Gorsuch concurred in the judgment but not the reasoning.

The ruling

The 6-3 decision in Chatrie v. United States holds that "an individual has a reasonable expectation of privacy in records about his cell phone's location, and police intrude on that constitutionally protected interest when they demand the information, even though for only a limited time, and from a third-party tech company." The court concluded that simply using services like Google's location history does not amount to voluntarily sharing private information with the government under the so-called third-party doctrine. Police now need a search warrant supported by probable cause to force a company to turn over geofence data.

A cellphone 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 cellphone users do.

The case

The case stemmed from a 2019 bank robbery in Midlothian, Virginia, where nearly $100,000 in cash was stolen from the Call Federal Credit Union. After the investigation stalled, detectives served Google with a geofence warrant seeking anonymized location records for all phones within a 150-metre radius during a one-hour window around the crime. The three-step process eventually identified Okello Chatrie, who was later found with cash, a gun, and a demand note. He pleaded guilty and was sentenced to nearly 12 years in prison. His appeal argued the warrant violated the Fourth Amendment because it allowed searching innocent people's data without individualised suspicion.

Legal implications

While the decision establishes that geofence warrants are a Fourth Amendment search, it did not resolve whether the specific warrant in Chatrie's case was reasonable. The justices returned that question to a lower court for further review. The ruling also stops short of banning the practice entirely; police may still obtain location data if they first secure a warrant that meets the amendment's particularity and probable cause requirements.

I cannot support this irresponsible escapade.

Justice Samuel Alito's dissent, joined in part by Justices Clarence Thomas and Amy Coney Barrett, warned that the majority's reasoning would "send seismic waves through our Fourth Amendment doctrine." The Trump administration had argued that users lacked a reasonable expectation of privacy after voluntarily enabling location services on their devices.

Reactions

Civil liberties advocates welcomed the ruling. Andrew Crocker, surveillance litigation director at the Electronic Frontier Foundation, said the court "reaffirmed that you have an expectation of privacy in location data that reveals your movements in the physical world, and that even short-term surveillance of these movements is a search subject to the Fourth Amendment." He criticized the decision for not going further, noting that the court left open how broadly warrants may be drawn.