Earlier quoted context omitted.
All of this debate is pretty irrelevant since refusal to unlock a phone is reason for police to hold you indefinitely until you unlock it. It's a misconception that locking with a passcode means you've "defeated" the police somehow. Most officers probably won't deal with the hassle, but if the officer is in a particularly bad mood or if they have reason to suspect you actually do have something incriminating, the off…
False. CBP yes. Police no. You do not have for follow their orders except for their safety. They'll have to drag you before a judge to force you to unlock it. And even then it is questionable is providing a password is protected constitutionally. Courts have ruled differently on this.
The "questionable constitutionality" of it is irrelevant since in practice until there is a higher ruling on this, if you don't want to go to jail, you must give up your passcode.