It's funny how even a small shift in tone can make a difference. I was recently screened at Heathrow and I alarmed the metal detector. (I can always wear my belt in the US without it going off, but I forget that doesn't always work overseas).
The security screener politely says:
Excuse me, sir. Would it be alright if I search you?
He proceeded to very politely describe where he would be doing, etc.
Can you ever imagine a TSA agent initiating a pat-down that way. It's always delivered instead with phrases like "You need to..." I think a mere change in tone could go a long way to improving security...it certainly made me want to cooperate more.