The Supreme Court held Monday that constitutional privacy protections extend to cellphone location information, ruling in the case of a bank robber whose identity was discovered through a geofence warrant.

Justice Elena Kagan wrote for the 6-3 court that people don’t forfeit expectations of privacy even when they opt into Google’s location history.

“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,” Kagan wrote.

Justice Samuel Alito wrote in dissent that Okello Chatrie had no expectation of privacy in information he voluntarily turned over to Google.

The decision is the court’s latest effort to apply a constitutional provision ratified in 1791 to technology the nation’s founders could not have envisioned.

Police obtained a geofence warrant after a bank robbery in a suburb of Richmond, Virginia, and used it to locate cellphones that were near the bank around the time it was robbed in May 2019.

One of those phones belonged to Chatrie, who had eluded the police until they turned to the powerful technological tool.

The warrant kick-started the investigation. After determining that Chatrie was among those near the Call Federal Credit Union in Midlothian at the time, police obtained a search warrant for his home. They found nearly $100,000 in cash, including bills wrapped in bands signed by the bank teller.

Chatrie pleaded guilty to robbing the bank and was sentenced to nearly 12 years in prison. His lawyers argued on appeal that none of the evidence should have been used against him.

They challenged the warrant as a violation of his privacy because it allowed authorities to gather the location history of people near the bank without having any evidence they had anything to do with the robbery. Prosecutors argued that Chatrie had no expectation of privacy because he voluntarily opted into Google’s location history.

The Supreme Court did not decide Monday whether the search complied with the Fourth Amendment, which bans unreasonable searches and seizures. It sent the case back to a lower court for more work.

A federal judge had ruled that the search violated Chatrie’s rights, but allowed the evidence to be used because the officer who applied for the warrant reasonably believed he was acting properly.

The federal appeals court in Richmond upheld the conviction in a fractured ruling. In a separate case, the federal appeals court in New Orleans ruled that geofence warrants “are general warrants categorically prohibited by the Fourth Amendment.”