The Privilege to Bear Arms?

I saw a bumper sticker a couple of days ago that said, “Buy a gun: Piss off a liberal!”  I consider myself to be liberal in regard to most things, and frankly, someone buying a gun doesn’t bother me in the least.  It’s a Constitutional right; if someone wants to own a gun, that’s his business, and I have no problem with responsible gun ownership.

However …

On the same truck was another sticker that read, “If I had killed you when I wanted to, I’d be out by now.”

Is this person deserving of the right to bear arms?