That doesn't always work out that well for the person "forgetting" the password though: https://en.wikipedia.org/wiki/Key_disclosure_law

Exactly, this depends a lot on jurisdiction. I seem to remember that there are some places where you could basically spend the rest of your life in jail if you forget (with or without scare-quotes) your passport.

Yeah... It's like child support laws here where I live (never had to pay child support, have a friend that is a lawyer). They can hold you indefinitely until you come up with what they need. Forgot the password? Ah well, how convenient! We have this place just for you to sit and hopefully.one day remember!

Child support here, while I agree it should be being paid but people can run into hard times, is sort of like this but more ridiculous. If you are.behind on child support, they jail you indefinitely until you can pay it.... But you are in jail indefinitely and likely have lost your job if you had one. So....

That's a choice however, assuming you know it.

on iPhone, you can press the `power` and `volume down` buttons for a few seconds and Face ID is disabled until you enter the code.

On Android, this is (usually, vendors may vary) hold down `power`, then tap "Lockdown" on the screen. I do like the fact that on Apple you can do it without interacting with the screen.

Similarly, tapping the power button five times in close succession will put an iPhone into "emergency mode", which (a) brings up a screen with prominent buttons to call 911 or your emergency contact and (b) disables biometrics until the PIN is provided.

Volume up works too.

You are right. I incorrectly assumed that since `power` + `volume up` takes a screenshot, it wouldn't work, but I just tried it, and holding them for a few seconds does lock the phone too.

Clicking power 5 times also seems to work!

In the US, the idea isn't that the password can be forgotten, but that passwords are protected speech, which can't be compelled. This legal theory hasn't been fully tested, though — I wouldn't depend on it unless it was upheld by the Supreme Court, but I'd expect this Court to give the police absolutely anything they want.

This isn’t true in most of the world and is even questionably true in the US

It will remain questionable in the US until it reaches the Supreme Court.

IMO is clearly a violation of the 5th amendment, but the Bill of Rights in the US has been soo watered down at this point they may not even be considered rights any more....

4th amendment, I think. Regardless, given the current composition of the Court, I wouldn't hold your breath for the situation to improve.

One could make that case, but 4th allows for searches with a warrant

I would say 5th because divulging the contents of ones mind is testimony which one should not be compelled to do, the 5th profits you from being a witness against yourself, reveling a password is being a witness against yourself

Fifth: the password is testimony. It's searching their things, but the warrant issued by the court means that it's likely a reasonable search (ergo, not a violation of the 4th).