At LHR security about 2 years ago, the guy in front of me refuses to remove shoes after being asked. After arguing with security he takes his shoes off, slams them on the belt, and then says (thinking he is joking) "GREAT, now your going to find my bomb!" This resulted with him on the ground with 3 cops on top of him arresting him and security being shut down for 30 min. What a moron.