For an argument that searching a U.S. citizen's cell phone at the border requires a warrant, and that the practice of warrantless searches is unlawful under Riley v. California, see my new book, "The Digital Fourth Amendment."
https://www.amazon.com/Digital-Fourth-Amendment-Privacy-Policing/dp/0190627077
https://www.amazon.com/Digital-Fourth-Amendment-Privacy-Policing/dp/0190627077
Comments
But am I right in removing all social media from my phone?