> In Britain for many years the main security measure at Heathrow was for security people to simply interview passengers on check in and ask them about their ba

> In Britain for many years the main security measure at Heathrow was for security people to simply interview passengers on check in and ask them about their bags, where they were traveling, etc. -- the main purpose was to look for behavioral cues and not so much obtain answers to the questions. I believe this is one of the things TSA officers are supposed to receive training in. This is the case in US airports as well. I recently flew back to Belgium from JFK in NYC. Before you go through screening you get asked those questions by someone, who then writes something on your boarding pass.