The U.S. Supreme Court summed up their thoughts on searches of cell phones by police in one short comment. "Our answer to the question of what police must do before searching a cell phone seized incident to an arrest is accordingly simple," Chief Justice John Roberts said in the Court's opinion covering warrantless searches of cell phones, "get a warrant."
The unanimous decision was in response to two cases before the court, one, Riley v. California, was in regards to a smartphone seized during a gang related arrest. The other, United States v. Wurie, was in regards to a flip-phone seized in a drug-related arrest. In both cases, information on the phones led police to evidence that in turn led to arrests on additional charges.
In both cases, law enforcement officers said that they examined the phones because the defendants were in possession of them at the time of their arrests. Normally the courts have held that police may search individuals when they're arrested to protect police from weapons and to preserve evidence. However, the protection of the law enforcement personnel is the primary reason for allowing any warrantless search. To examine anything found requires a warrant.
In deciding this case, the Court, which has often been accused of being out of touch with current technology, showed no such limitations in this case. It was clear from the opinion that the Justices understood the difference between mobile phones and other things a person, criminal or not, might carry.
"Cell phones differ in both a quantitative and a qualitative sense from other objects that might be kept on an arrestee’s person," Roberts said in the Court's opinion. "The term 'cell phone' is itself misleading shorthand; many of these devices are in fact minicomputers that also happen to have the capacity to be used as a telephone. They could just as easily be called cameras, video players, rolodexes, calendars, tape recorders, libraries, diaries, albums, televisions, maps, or newspapers."
Roberts went on to describe the vast storage capacities of today's smartphones, and that before these devices appeared one would be limited by the physical realities of storage and transportation if they wanted to carry such large quantities of information around.
"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 pointed out.
Roberts also noted that one thing that has changed as a result of the digital revolution is the element of pervasiveness. He pointed out some estimates that indicate 90 percent of American adults have a cell phone. He also noted that those phones now carry a cache of sensitive and personal information including details of where they've been, private medical details and a range of other information.