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.
Don't worry, they're working on ending birthright citizenship
The U.S. isn't China or the UK.
In my experience, Australia was the most difficult country to get into as they are (now) very careful about bringing in any plant seeds or fruit, but the security staff were very friendly and helpful. I had to spend a while explaining that I did have some bananas in my bag previously which was why the cute sniffer dog was interested in it.
https://www.libertyhumanrights.org.uk/advice_information/exa...
Wasn't. Past tense.
Under what grounds?
I'm not saying that I agree with it, it's just the way it is