I was just in Boise Idaho airport this past Thursday. The guy right in front of me put his carry-on bag onto the conveyor to go through that screening tunnel. Well, lets just say it about shut down the airport for about 5 minutes. The alternate TSA personnel were saying he has a gun,(in his bag)and its loaded.
The guy really did not look like he had any bad intentions. But glad they were watching. I am sure that cost him some pocket change.