Nah this is just Trump's social media policy. Clearly it extends to friends and perhaps friends of friends. It should be pressed in the courts and maybe Congress should get involved. I mean we do recognize freedom of speech in this country and freedom of association. Since this kid had a valid Visa so the vetting should have been done and the bar to invalidate that visa should be high. That being said, it seems wise for people to purge their social media before visiting the US. It also seems wise not to have US social media accounts.