One is knowledge the user has, and the other is a physical key they own.

Providing your 'finger' to unlock a device is no different than providing your 'key' to unlock something. So you can be compelled to provide those biometrics.

Compelling you to reveal a password is not some *thing* you have but knowledge you contain. Being compelled to provide that knowledge is no different than being compelled to reveal where you were or what you were doing at some place or time.

That is genuinely the current state of law, yes. There's no real logic at work, just attempts at clawing back control whenever a new gray area appears.

> So in america, they can force you to use a biometric but they can't compel you to reveal your password?

I don't get it, touching finger is easy, but how do you compel someone to reveal their password?

Pretty much.

Something you are: can be legally compelled Something you have: can be legally compelled Something you know: cannot be legally compelled

Yes the difference come from a close parsing of the 5th amendment, telling cops the password or code for a device or safe is pretty clearly compelling speech and adverse testimony while allowing cops to gather fingerprints and DNA has long been held as allowed so biometrics were analogized to that. It's also similar to the rule that cops can't force you to tell them the code to a safe but they're allowed with a warrant to destructively open the safe (if it falls under the terms of the warrant). Combine those too legal threads and it's at least reasonable to see how that line gets drawn from previous rulings.

Germany does the same thing too . They can force you to unlock via faceid/biometric but can't force you to enter password.