On a four segment trip this week, I was "selected" three times for the bogus secondary screening. Notwithstanding that the 9-11 hijackers would easily have passed this "rigorous" screening, I noticed that only older white males were being selected.

My theory has nothing to do with class warfare or PC, as others have suggested, but I think the screeners deliberately pick out the people who are least likely to be real terrorists (older folks, businessmen, etc.), as your average older white male isn't going to give them any lip, is easily searched, and this gives the screeners the ability to look like they are actually doing something wthout incurring any real risk to their job or safety.