The Supreme Court will hear a major case on how authorities can gather cellphone data

The Supreme Court said on Monday that it would hear arguments in a critical digital privacy case that could set new limits on the ways that law enforcement can obtain suspects’ cellphone location data.

The fight coming to the country’s highest legal bench concerns a 2011 robbery investigation in Detroit. Investigators at the time relied on a little-known federal law, known as the Stored Communications Act, in order to gather 127 days’ worth of past location information about one of the suspects, Timothy Carpenter, without first obtaining a warrant.

Telecom companies collect and maintain these customer records — bits of information that associate text messages or phone calls with nearby cell towers — as part of regular business.

But authorities around the country increasingly have sought to tap that trove of data as part of their investigations, and in Carpenter’s case, the information that police obtained appeared to place him near a series of robberies, which targeted Radio Shack and T-Mobile stores.

A lower court ultimately convicted him, but Carpenter challenged the ruling, and with the help of the American Civil Liberties Union, he has argued that the ability to obtain historical cellphone location data — without probable cause — violates the Fourth Amendment, which prevents unreasonable search and seizure.

If the Supreme Court agrees, it could require law enforcement officials to obtain and demonstrate greater proof that a crime might have occurred before they could obtain information about a suspect’s whereabouts.

“Because cellphone location records can reveal countless private details of our lives, police should only be able to access them by getting a warrant based on probable cause,” said Nathan Freed Wessler, staff attorney with the ACLU’s Speech, Privacy and Technology Project, in a statement. “The time has come for the Supreme Court to make clear that the longstanding protections of the Fourth Amendment apply with undiminished force to these kinds of sensitive digital records.”

For years, Congress has sought — unsuccessfully — to revise a number of dated federal laws that govern when, and how, law enforcement agencies can obtain digital records from phone companies, internet providers and other tech giants. In the meantime, though, the Supreme Court has been asked to rule on a number of pressing digital privacy issues, and in some instances, the nation’s justices have stipulated new limits.

In a 2014 case, for example, the justices found that warrantless searches on suspects’ cellphones at the time of their arrest violates the Fourth Amendment. Two years earlier, the Supreme Court ruled that law enforcement also needed a warrant before engaging in round-the-clock tracking of a suspect’s vehicle, which constituted a search.

Five justices who ruled in that unanimous decision, Jones v. United States, still remain on the court, said Jake Laperruque, senior counsel at the The Constitution Project. For that reason, he said, “it seems like there’s a very good chance the Supreme Court will take a more sympathetic view.”

“At a minimum, it’s going to be a really big deal for location privacy, and it’s got the potential to be much broader than that,” he added.

This article originally appeared on Recode.net.