It ONLY applies to citizens. The CBP cannot deny an American citizen entry into the country for any reason. They cannot compel a citizen to unlock their devices. All bets are off for non-citizens, sadly.
> The CBP cannot deny an American citizen entry into the country for any reason. They cannot compel a citizen to unlock their devices.
Don't worry, they're working on ending birthright citizenship
Actually, I'm not sure they can compel non-citizens. If you want in, you might have to give them the keys. But if you would rather not enter, would they compel on pain of imprisonment?
The U.S. isn't China or the UK.
They can't prevent you from entering the country. You do not have an unlimited right to bring items into the country with you, though. They can absolutely prevent you from bringing your phone across the border if you decline to unlock it