Cops can force you to unlock your phone with your fingerprint, but not with your passcode, according to a judge in the US state of Virginia.
We touched on this in early 2012 in United States: ID Technology & the Bill of Rights which drew inspiration from a bank fraud case in Colorado.
I still think that voice-based technologies may still exist in the legal gray area this case attempts to clear up.
As for fingerprints, those may be taken from persons at the time of their arrest, so it’s hard to argue that they are somehow out of bounds for investigative purposes. One may be forgiven, however for wondering what’s the big deal. After all, I’ve been reading for years that finding a latent fingerprint and using it to hack biometric security systems is child’s play. So, either the police would rather go to court than use such a simple workaround, or the rubber finger trick is much harder to pull off than some suggest.