In a unanimous ruling, the U.S. Supreme Court decided in Riley v. California (court pdf; archive pdf) that the police need search warrants to search individuals’ cellphones after their arrest, which is a substantial victory for privacy rights. (Note: This decision is issued for two cases – Riley v. California, No. 13-132, and United States v. Wurie, No. 13-212. Riley concerned two searches of a smartphone after David Riley was arrested, and Wurie concerned the search of a flip phone after Brima Wurie was arrested.) Chief Justice John Roberts wrote the opinion for eight of the justices. Justice Samuel Alito joined in the judgment, but he wrote a separate concurrence.
In the opinion, Justice Roberts noted that cellphones, “are now such a pervasive and insistent part of daily life that the proverbial visitor from Mars might conclude they were an important feature of human anatomy” and “Cell phones, however, place vast quantities of personal information literally in the hands of individuals.” He explained, “[W]e generally determine whether to exempt a given type of search from the warrant requirement ‘by assessing, on the one hand, the degree to which it intrudes upon an individual’s privacy and, on the other, the degree to which it is needed for the promotion of legitimate governmental interests.’” In this case, the justices found that individual privacy trumped government interests.