As a regular flyer for my job (4/5 times a week), I have for the past few months wondered what criteria decides whether the passengers have to take their shoes off or not at security screening. It does seem to be a random percentage thing, ie 1 in 3 or 1 in 4 people have to take their shoes off (not sure what the actual number is).

All except LHR, that is, and I always wondered why. Yesterday at security at LHR T1 Domestic, I finally got it. Whilst waiting in the queue I observed that no-one was being asked to take off their shoes. Then all of a sudden the music coming over the tannoy changed to the theme tune to "Footloose", and everyone was being asked to take off their shoes. Then the song finished, and we were back to no-one being asked.

Have I cracked their ultra-secure system ? If I know any shoe-bombers should I tell them to avoid periods of cr*p 1980s songs playing over the tannoy ? Should I inform MI5 ?????