Some scanners are programmed for random stops so even if you went through stark naked it could still flag you for a search, just in case anyone is wondering why some days you beep and some you don't even though you're dressed exactly the same.
X-ray machines randomly display an image of a gun in a bag going through the machine to check if the operator is actually paying attention.
Some of these to**ers are working as security screeners because they failed the intelligence and personality tests to be wheel clampers.