I don't think they can deny entry (but do check the source for that), but I think it means they just made it explicit that they might dig into the "social" acco

I don't think they can deny entry (but do check the source for that), but I think it means they just made it explicit that they might dig into the "social" accounts and ask questions. They (the government) probably already monitor and record stuff like that, but now are exposing it directly by asking related questions, say "You bought a pressure cooker, and a ball bearings last month, saw it on your Amazon account. What are you planning on doing with those".