Police may not generally search the cellphones of people they arrest without first getting search warrants, the Supreme Court ruled Wednesday.

The court said cellphones are powerful devices unlike anything else police may find on someone they arrest. Because the phones contain so much information, police must get a warrant before looking through them, Chief Justice John Robert said.

The Supreme Court previously had ruled that police could empty a suspect’s pockets and examine whatever they find to ensure officers’ safety and prevent the destruction of evidence.

The Obama administration and the state of California, defending the cellphone searches, said cellphones should have no greater protection from a search than anything else police find.

But the defendants in these cases, backed by civil libertarians, librarians and news media groups, argued that cellphones, especially smartphones, are increasingly powerful computers that can store troves of sensitive personal information.

In the cases decided Wednesday, one defendant carried a smartphone, while the other carried an older flip phone.

“Modern cellphones are not just another technological convenience. With all they contain and all they may reveal, they hold for many Americans the privacies of life,” Roberts said. The court’s answer to what police must do before searching phones is simple: “Get a warrant,” he said.

(AP)