Originally Posted by
exerda
I've had it happen in countries where TSA isn't involved at all, FWIW (e.g. BKK-NRT). Random-esque it may indeed be, though the UA staff I spoke to on a couple of occasions (once in Asia, once in Europe) insisted it was "DHS" who flagged me--which is a case of a lying or misinformed agent, given my name isn't remotely like any on any list and I am a DHS Trusted Traveler via GE.
That's true. When you complain they tell you "that your country demanded that we do this." This is of course nonsense. The US might create an alert due to some bogus reason, but the implementation is up to the country in question.