Protesters demonstrate outside the Federal Bureau of Investigation (FBI) headquarters building in Washington, DC, February 23, 2016, objecting to the US government attempt to put a backdoor into the Apple I-Phone. Apple is battling the US government over unlocking devices in at least 10 cases in addition to its high-profile dispute involving the iPhone of one of the San Bernardino attackers, court documents show. / AFP / PAUL J. RICHARDS