Re: The worst customers...
Going even further off-topic, I heard from a friendly PC once about the new Chief Constable turning up at a local police station, and trying to walk into the back areas without presenting ID, taking the "Don't you know who I am?" line to the desk Sergeant (followed of course by explanation of who he was) but refusing to provide ID. Eventually, the poor Sergeant let him through, at which point the Chief Constable turned round and roasted the guy for letting him through without ID - the whole thing was a test of how well the staff were prepared to stand up to such behaviour/social engineering.