In United States v. Cano, the Ninth Circuit Court of Appeals held that certain limitations apply to searches of cell phones at the border. First, the search must be limited in scope; the search must be conducted to discover digital contraband, not evidence of a future crime. Second, if the search is forensic, meaning the search greatly intrudes upon the privacy of an individual, the search is only valid if the government actor had reasonably believed that the cell phone possessed contraband.
United States v. Cano: The Ninth Circuit Limits Warrantless Searches of Cell Phones at the Border, 50 Golden Gate U. L. Rev. 49