There's also the fact that driving is many times more dangerous than flying, yet flying gets the most "security" (not that I want a TSA pat-down before getting into my car, of course, but it just shows how useless they are).
By the way, the backscatter devices would NOT have detected Mr Underpants Bomber. Oh, and every policy the TSA has put in place has been after someone got through security (e.g. shoe bomber => take your shoes off). Security theater at it's finest. Now, who are the politicians who've gotten donations from Rapiscan et.al. and how do we make sure they're permanently removed from office?