two quick comments:
1) As JaWib pointed out. This is security theater. period. It is only necessary to make the mouth breathers feel safe. There's nothing more comforting to rural American masses who fly once a year than seeing a brown person getting the shake down at a security checkpoint. Tax dollars at work...
2) It's hilarious for me to see gun nuts like steve perfectly willing to see the government trample all over the 1st, 4th and 5th amendements, which are MUCH more relavent to life in today's world than the 2nd. I guess having your guns makes you feel safe from your government, but sadly that's not the case.