Criminals usually aren't very intelligent, but when you get those who have some intelligence, you end up with the aforementioned situations: perps following people home, breaking into CCW-bumper-stickered cars, etc.
I agree with you, though. Don't advertise what you have.
If I put a supercharger on my pickup I sure wouldn't go slap the brand's sticker on the back of the bumper.
I once considered using the ARFCOM bolt-face bumper sticker, but I figure if I need more gun-totin buddies I can just go to a different gun range.
Among the first rules of CCW/self-defense, IMO, is to use situational awareness to reduce your incidence rate with criminals. Secondly, since criminals are the ones initiating contact, you do not want to provide them with any reason to initiate contact in a different manner than if they thought you were unarmed. If a criminal's desperate enough, has a gun and knows you're armed, they might initiate contact by shooting first. They can, of course, do that to the unarmed, but you do not want to provide that option to them as their first and only course of action.
Just my two cents.
