The U.S. Supreme Court earlier this week heard oral argument in two cases involving whether the police, after arresting someone, can search his or her cell phone without a search warrant. Although the police have been allowed to do a limited search of a person after they’ve been arrested, this exception to the Fourth Amendment’s warrant requirement was never intended to cover the massive amounts of sensitive information on a cell phone. But as the oral arguments made clear, the government is relying on dangerous misconceptions about cell phone technology in an attempt to justify a significant privacy intrusion.