Biometric device unlock

 
 In smart phone and other devices the trend is to add biometric features. You can unlock smart phones with finger prints for some time. That feature uses advanced technologies to prevent someone taking your finger or fingerprint to unlock your iPhone, iPad, or other smart device.

  In today's news an article wherein the FBI is requesting fingerprints of everyone in a California property,  This will spawn legal challenges but the current precedent is to allow this

 Some devices recognize your face to logon or unlock. Iris scanners, palm print scanners, the list of biometric methods will likely grow.
 This makes for convenience for the user, Can't forget your fingerprint.
 Consider your device is setup to unlock by scanning your face, Someone steals your unattended  phone. You start scanning the location looking for the device. The thief scans your panic face, unlocks the device, replaces your face with theirs,
 
 Most devices allow multi-factor unlock and/or login. PIN, and passphrases have their advantages and disadvantages. Consider utilizing both biometrics and PIN/passphrases. Doing so might prevent someone else gaining access by tying you up, anging you on the head, or ...