That's definitely an added measure of security should someone decide to rob you of your gun collection, but that's not really the point I was making. More that this type of sign would make you a likelier target for criminals wanting to score guns(which is plenty), not make you easier to rob. If most burglaries occur in the daytime when folks are not at home, why make a point to show it off. That's like putting a sign on your windshield that says "KICKASS SYSTEM IN HERE".
EDIT: With the limited research into this subject that I have gleamed off teh webs(grains of salt and what not), it doesn't seem terribly uncommon to have the whole safe stolen. I was even reading a story someone posted about their closet floorboards being sawed through to defeat the bolts. Which in my line of reasoning would indicate that there are at least some thieves out there who know exactly what they are looking to get, and can logically set expectations about possible security measures. If you were a thief and you were wanting to steal guns where would you go and what would you bring ? Obviously a place you know has guns. Bring a couple of your equally worthless friends, a dolly, a truck and some tarp, a saw. Just seems to me that the best security should first be discretion, then backup solutions.
I do have a question though, if your guns are locked up so tight, and you hear your door get kicked in, and are the victim of an actual home invasion, say at night, disoriented, off-balance, wouldn't having such a secured setup be a hindrance ? Not necessarily to you either Scott, because you have military training and experience, but a civilian that has reasonable gun experience, such as myself. Which is exactly why I keep my shotgun loaded and easily accessible in my bedroom (to an adult anyway). I do understand that having such a sign as posted could deter a would-be home-invader during nighttime hours, but do you think it would deter anymore than say a "Brinks" sign, or a "Beware of Dog" sign ?