If they ever caught one. Imagine a bad guy being caught. He would just put his hands up and say "Fair cop, Gov!"
Or the lone lawman, usually a fat, slow local cop (and I am not exaggerating) with a 9mm pistol would have to take him down.
If this guy was armed, guess who is in the crossfire?
You!!!
What will the TSA do then; have security set up for people to go through so that they could go through security?