Multi-factor
I've always seen biometric authentication as a lazy way to access your device. Ease of access is the reciprocal of security. The other downside is if you die or are in hospital, nobody else can get into your device such as a spouse, close friend or family member via a sealed envelope you have left with codes inside for that purpose.
The one thing I suggested before was to have a facial recognition system where you get access if both eyes are open and your device wipes itself if you have one eye closed. You could even have it set to only wipe a certain folder leaving your more mundane data in place to make it appear you have complied fully with a police/court request. Fingerprints could be the same way. Use your middle finger for normal access and your index finger for access that gets rid of incriminating folders since using an index finger is most common, it won't look odd if you do it that way. The best thing is to just not put things on your phone that will get you in trouble. The filth could walk up behind you while you are buried neck deep in you device and just snatch it from you while it's unlocked and keep it active manually or through one of their clever little devices.
Biting the hand that feeds IT
