Originally Posted by Prospero
Only speculating but I would imagine there must be surveillance measures in place to catch out any passengers arriving off a transatlantic flight and using the EU customs channel.
Yes - for the first time the other day (ever), I was stopped at LHR. Coming off the morning BUD flight (first off, through IRIS, past a big passport queue ^, hand luggage only so merrily striding through towards the Blue channel minding my own business) I looked up and saw about 10 Customs bods standing by all the exits - I figured there must have been a tip off of some kind. As I approached the guy stopped me and asked where I was coming from. Cue a quick moment of panic as I had to think for a second where I was actually coming from that morning (early starts + me = disagreement)
He asked if I'd come from anywhere else before BUD and I said no, and with that he left me to go through the Blue line. I thought that some people, off some flight were going to get a going over!