Just thought it may be beneficial for everybody.
I know a fellow who is a director of a certain aircompany headquaters in Zurich. What he told me once was rather interesting:
He said that the Department of State obliges all carriers for America bound flights to slide all US passports (RTD and RP included) or US visas before boarding. Thus, the US authorities are getting the info of who is coming before the plane even reaches the destination. I never paid attention, but after he told me ,I then started to look out 4 this, and -Bingo - they slided mine and my wife's entry visas (we didn't have asylum at a time).
Now, what do they do with this info... who knows...
Whether this info goes to customs? ins? irs
But technically speaking it sounds like it's very easy to track anyone's whereabouts (or at least where the person travelled from).
Any ideas, anyone?