I once took my bike on holiday, and the guy at MAN wanted to X-ray it.
Thing is, a 21" mountainbike doesn't fit through the machine too well. He tried all kinds of different positions then said "Ah well we'll have to go back to the manual procedure" as if it was something they are taught. He then 'felt up' the nuts (on the bike I mean) and wiggled the saddle a bit and said 'fine' letting me check it in.
I think he did that so as not to lose face. Because if I had wanted to use my bike as a bomb I'd have loaded the frame tubes with semtex. He didn't think to check the tubes though.