This was coming. an Appeals court ruled that forcing an arrestee to place his finger on a phone to unlock it is no different that compelling a paper fingerprint record or a DNA sample.
Once again, this is what your physical characteristics are not WHAT YOU KNOW, thus not subject to Fifth Amendment protections.
So the moral of our story. Don’t use biometrics in securing any digital devices if you have data on them that may be misunderstood or used against you in court. Fingerprints or even facial recognition. A longer than 4 digit pin would be best. They can be hacked but take time and a lot of money, even then may not be admissible in court.
If you are using powerful encryption programs to secure your data, then use the appropriately strong passphrase to protect it. Ideally one that equals the entropy of the symmetric algorithm used for that encryption. That way, rainbow tables will take the years of guessing that brute forcing the key will take.
My fave description of a passphrase generator-
http://world.std.com/~reinhold/diceware.html
An overview of current court rulings as to opening or decrypting digital devices and data.
Ridge