That thing about unreasonable search? OH! it doesn’t apply in airports. Funny, the Constitution says nothing about airports being an exception.
Still think it’s the land of the free?
I travel internationally very frequently. I have never been asked to unlock my phone. And, if I ever am? My answer will be “No”.
If that means I get denied entry at the border? Then, I’ll return home... or, sit in their jail till Trump gets me out.