U.S. investigators are exercising a broad legal authority to force suspects to unlock their smartphones. In a recent case, they demanded that anyone found inside a California residence comply by surrendering their fingerprints. In May, the federal prosecutors made the request as part of a search warrant. It comes as law enforcement agencies have been trying to find ways to bypass the security on smartphones. Despite the Fifth Amendment, a court in Virginia ruled in 2014 that compelling suspects to hand over biometric data, including fingerprints, is still legal.”]