U.S. Supreme Court's Cellphone Ruling Is a Major Victory for Privacy

The Supreme Court enshrined some digital privacy with its ruling Wednesday Gary Cameron/Reuters

Police cannot search arrestees' cellphones without a warrant, the U.S. Supreme Court decided on Wednesday.

The unanimous ruling marks a watershed moment for the digital rights movement, applying the Fourth Amendment—which protects against unreasonable search and seizure—to most data on the pervasive devices, potentially setting a precedent that favors privacy. The court considered two cases on the issue of digital searches, Riley v. California and United States v. Urie. The question in both cases was whether police can search cellphones of people they arrest without a warrant.

Law enforcement agents have long been permitted to search arrestees without a warrant upon apprehension. The rationale stems from safety and evidence-protection purposes—a police officer needs to know whether a perpetrator is armed or carrying contraband. This exception called a "search incident to arrest." In both cases, law enforcement authorities argued that right allowed them to search cellphones as well.

Chief Justice John Roberts, who authored the opinion, maintained that searching a cellphone without a warrant constitutes a different, deeper privacy intrusion and that such warrantless searching protects neither officers nor evidence.

Comparing physical and digital searches, he said, "is like saying a ride on horseback is materially indistinguishable from a flight to the moon. Both are ways of getting from point A to point B, but little else justifies lumping them together."

Because the devices nearly all of us carry in our pockets have so much storage capacity, and because so much of the information stored would, in physical form, extend beyond a mere physical search, a warrant is required, the court decided.

"Most people cannot lug around every piece of mail they have received for the past several months, every picture they have taken, or every book or article they have read—nor would they have any reason to attempt to do so. And if they did, they would have to drag behind them a trunk of the sort held to require a search warrant," Roberts wrote.

In addition, the search incident to arrest exception "may not be stretched to cover a search of files accessed remotely—that is, a search of files stored in the cloud."

"The fact that technology now allows an individual to carry such information in his hand does not make the information any less worthy of the protection for which the Founders fought," Roberts also wrote.

"Our answer to the question of what police must do before searching a cell phone seized incident to an arrest is accordingly simple—get a warrant."

While recognizing that "our decision today will have an impact on the ability of law enforcement to combat crime," Roberts wrote that "privacy comes at a cost."

Hanni Fakhoury, staff attorney at the Electronic Frontier Foundation, which filed amicus briefs to the U.S. Supreme Court supporting cellphone protections, told Newsweek that the decision could affect several pending court cases.

"Some of the discussion in the court opinion that talks about technology can very easily be parlayed into other court challenges," he said. "It triggers a different way of looking at the Fourth Amendment. That's something that's going to play a very large role in the debate and in the legal challenges with NSA surveillance and cellphone tracking."

One way of interpreting the Supreme Court's decision is that obtaining a lot of information without a warrant does not meet the criteria for search incident arrest, and that idea could be applicable beyond smartphones.

"Obtaining a whole ton of information about a person is different than just a small little bit of information," Fakhoury said. "That aggregation matters, and I think that will come up with the NSA cases or any other scenario."

A case on cellphone tracking currently pending in the U.S. Court of Appeals for the 4th Circuit might be immediately affected by Wednesday's decision, as the court specifically stayed the case to see what the Supreme Court would decide, Fakhoury said.

The case does offer some wiggle room for authorities: Cops can still search cellphones in the case of obvious emergencies.