I have always believed that advertising any kind of "gun stuff" will attract the interest of a number of criminals. And the dangerous ones won't be deterred by any warning sign. Besides it's so much more fun when you can "surprise" them.
In all seriousness I hope I am NOT home when the bad mens come. I used to travel around a gun show circuit with a bunch of dealers. None of them had any bumper stickers on their trucks or trailers. Even still, one night two of them were sitting in the motel restuarant talking about "business" while a couple of guys were overhearing everything they said. About 2 am they hit these dealer's rooms and got all of their merchandise and cash. Unloaded their trucks in the parking lot. Made me think about it. I always liked Roosevelt's line...."walk softly and carry a big stick." The best thing you can do for home security is remove/modify shrubs and trees around the house so you can see all of the yard and have lights on. A dog is the best motion sensor around.