I didn't visit US and I don't intend to do it soon(ever?), but I would have some "cartoonish" fears like: being detained/harassed/turned back in the airport for

I didn't visit US and I don't intend to do it soon(ever?), but I would have some "cartoonish" fears like: being detained/harassed/turned back in the airport for possible stupid/hostile remarks I made (who knows when, who knows on which forum) about US gov or foreign policy; Or being shot without witnesses or strangulated to death by some psychopath policeman because "resisted arrest" and so on..