New York Times:

The police officers wrestled with Colin Cheung in an unmarked car. They needed his face.

They grabbed his jaw to force his head in front of his iPhone. They slapped his face. They shouted, “Wake up!” They pried open his eyes. It all failed: Mr. Cheung had disabled his phone’s facial-recognition login with a quick button mash as soon as they grabbed him.

The iPhone’s so-called “cop mode”, introduced with iOS 11, kicks in when you press and hold either volume button and the side button simultaneously for 2 seconds. It brings up the SOS screen, but also requires you to enter your passcode to unlock your phone, disabling Face/Touch ID.

The authorities are tracking protest leaders online and seeking their phones. Many protesters now cover their faces, and they fear that the police are using cameras and possibly other tools to single out targets for arrest.

Facial recognition on one side, cop mode on the other. This is the road we are on.