The United States Supreme Court's holding, of course, is not that the information on a cell phone is immune from search; it is instead that a warrant is generally required before such a search, even when a cell phone is seized incident to arrest. The Supreme Court's cases have historically recognized that the warrant requirement is an important working part of our machinery of government, not merely an inconvenience to be somehow "weighed" against the claims of police efficiency.
These two cases involved a search by policemen on the respective cell phones of the individuals they arrested. In one case, petitioner Riley was stopped for a traffic violation, which eventually led to his arrest on weapons charges. In the second case, respondent Wurie was arrested after police observed him participate in an apparent drug sale. Both accused were seized of their cell phones which the policemen accessed to obtain incriminating evidence. This led to their conviction. Both accused contend that any evidence obtained from accessing their cell phones without a search warrant should have been inadmissible as evidence.
Whether the police may, without a warrant, search digital information on a cell phone seized from an individual who has been arrested.
The U.S. Supreme Court unanimously held that the police officers generally could not, without a warrant, search digital information on the cell phones seized from the defendants as incident to the defendants' arrests. While the officers could examine the phones' physical aspects to ensure that the phones would not be used as weapons, digital data stored on the phones could not itself be used as a weapon to harm the arresting officers or to effectuate the defendants' escape. Further, the potential for destruction of evidence by remote wiping or data encryption was not shown to be prevalent and could be countered by disabling the phones. Moreover, the immense storage capacity of modern cell phones implicated privacy concerns with regard to the extent of information which could be accessed on the phones.