I brought up the video from the training session and we began to talk about it. When we got to the part in the video about advising people to look around for something to use as a weapon, (I think in the video one guy had a fire extinguisher and another had a chair.) my boss advised that he was going to stand behind me, and laughed!
He knows I carry, and the company policy allows certain employees to do so but we must CC.I asked him if he had noticed that the BG walked right past a no gun sign on the front of the building? He had NOT noticed the sign while watching, and I put in a little jab about how useless the signs really are. I reminded him that the only people the signs affect are license holders. I went on to say that the only guns the signs kept out were the ones that might be able to help you in a shooter situation.
We talked on for several more minutes and he listened to point after point for which he had no comeback. I haven't won the battle over the signs, but I definitely scored some points. You have to look for opportunities to bring up the subject without griping, and this video gave me the perfect opportunity.