Police must obtain a warrant in order to search digital information on a cell phone seized from an individual who has been arrested. Decided June 25, 2014 (argued April 29, 2014). Opinion of the Court: John Roberts → go there Applied: the Fourth Amendment → go there Topic: Fourth Amendment rights. Riley v. California, 573 U.S. 373 (2014), is a landmark United States Supreme Court case in which the court ruled that the warrantless search and seizure of the digital contents of a cell phone during an arrest is unconstitutional under the Fourth Amendment. Wiki link