Why Cops Can Use Face ID to Unlock Your iPhone

You lock your phone so other people can't access it. But how you lock your phone is an important factor in whether law enforcement can compel you to unlock it. Apple's year-old Face ID system is no exception. On Sunday, Forbes reported the first known example of law enforcement anywhere using a suspect's face to unlock a phone during an investigation. The question of whether cops can force someone to unlock their phone in the US for a search hinges on Fifth Amendment protects against self-incrimination--that no one "shall be compelled in any criminal case to be a witness against" themselves. Privacy advocates argue that this extends to the act of unlocking a phone, or generally decrypting data on a device.