I only have once, and it was under very special circumstances.
I was the facility security officer (personnel, document and physical security) for a cleared NASA contractor.
When the first Gulf War started, I went to my ignoramus, Klansman boss and told him we needed to program the access control system so that it didn't unlock the employee door automatically every morning. Being the drooling simpleton he was, he refused.
Shortly afterward, I was in the john in the basement around the corner from my office and across the hall from the space instrument assembly facilities. Somebody came in and said that everybody should immediately leave the basement and come to the lobby. I figured that there'd been some kind of hazmat spill in one of the labs.
When I got to the lobby, I found a bunch of people milling around aimlessly. Jokingly I asked somebody if there was a bomb threat. They said, "Yes".
Apparently one of the engineers in the basement got a bomb threat on his phone, telling him that the bomb was in his desk somewhere. He reported this to my moron boss, who told him to search his desk. Smarter than the average engineer, he told my boss to go **** himself and search the area himself. Rather than evacuate the building, this imbecile just collected everybody in the lobby without telling them why. Having at least several braincells to rub together, it immediately occurred to me that this was a fine way to get a bunch of people together so that you could shoot as many of them as possible, probably achieving as many casualties by trampling and crushing as by shooting.
The next day, I started carrying a brief case to work. Inside of the briefcase were a Safariland ballistic vest, my Series 70 Colt and a couple of extra magazines. I kept this up until the end of the war. I later found out that this was just one in a series of bomb threats which that jackass had neglected to tell me about. I had two bosses, the other for computer work. I called the non-stupid boss down to my office, told him what was going on, and told him that if anything happened, he should come straight to my office (behind a vault door), since I wouldn't give a plugged nickle for his chances with "David Duke" calling the shots.
There was no concealed carry in Ohio at the time. Bombings and mass shootings weren't authorized either. I figured that the penalties for getting caught unarmed in a terrorist massacre were much higher than those for carrying a concealed weapon.
I believe in obeying the law... just not at the cost of my own life.
