The right to own and to carry any weapon is often belittled using the extreme scenario of your neighbor having a nuclear bomb in his garage. Forget for a moment the fact that extreme cases make for really bad laws. If you have an absolute right to own any weapon, what can you do if your neighbor has a nuke?
If my neighbor had a nuke, and I thought he was that much of a danger to me, I would try to destroy his bomb or shoot him before he had a chance to use it. Then I would take my chances with a fully informed jury. "Self defence" applies here, as it does in any instance of imminent danger. My neighbor would also be able to claim "self defense" if he shot me when I tried to get him, so it would probably be better to try to reason with him first. If I felt he was so mentally unstable that reason would not get through to him, then I'd take my chances.
What I would not do is use this case to argue that since my crazed, nut-case neighbor wanted to threaten my life, and the lives for miles around, by keeping a nuclear weapon in his garage that government should ban me from owning guns or ban children from having and using rubber band guns. That is insanity.
