It could be fun to just propose it and watch the heads of NRA leaders explode over the idea. Notice how enthused they are over the idea of trigger locks that prevent use of the weapon than by other than the owner/authorized user.
The NRA is the largest supplier of free firearm locks in the country. Chances are you can go to your county sheriff and get a cable lock gratis and chances are it was supplied to them by the National Rifle Association.
