While everyone would like to think that all law enforment personnel are the jack booted thugs they've heard/read about they basically are just doing their job. And it does not get any easier on them or you when you walk up and try to give these people a hard time.

It comes down to preparation or panic: Will they be able to search everyone and prevent an incident? No. Will them searching a handful of bags make most people feel safe because they see law enforcement doing something? Yes. This is the real world, thinking that everything that life is going to be "fair" should of been outgrown.