I dunno. Maybe because I used to do research at a Chinese lab when I was a student? That was my impression when I was once questioned for many hours by DHS at the airport. It's impossible to get an answer. They are granted broad legal authority to screen foreign nationals.

No indictment. Nothing physical. But a lot of headaches like delays in visa/immigrant application :shrug:

It was obviously such a credible threat that they couldn’t get a judge to sign a real warrant and had to do a warrantless fishing expedition.