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.

Get in-depth coverage of current and future trends in technology, and how they are shaping business, entertainment, communications, science, politics, and society.