In that truism that non citizens have no rights and shouldn't even pretend to ask for them, persons visiting the United States might be required to give up their social media credentials to border agents as a facet of tightened security. Failure to cooperate may result in not getting into the country.
Now then, I'm as pro security as anyone. I certainly envision border security as one of those aspects which enhances our safety ...
BUT As I said earlier when HR departments were doing the same thing that it's a positively Nazi position to require anyone to give up any password on any account they own — and blood likely would be drawn depending on how quickly I could grab the offending person by the throat and stop their breathing.
As I have repeatedly stated the problem with the Nazi party in general was that nobody would tell them "No".
Luckily, I have no social media accounts to which one might gain access. I wonder how that is going to work out for those attempting to cross the border. Sometimes we tend to turn jingoistic in our fervor of protectionism. There are places where a government may not tread and any password or credential I have is in that pathway.
If a foreign country were to try to coerce me into relinquishing any social media credential for absolutely any reason I'd likely be put in jail. Most likely death row if they have one. Nay nay a thousand times nay ... and anyone who asks that of me is a scoundrel of the lowest order. Far below used car salesman or even mill supply house owner.