Regardless - it is a cannon. And there are some out there that have been stolen [isn't it 50?]. So we know some criminals have them.
Let's not fall into the trap of letting the other side define our terms, like assault weapon and high capacity magazine. The .50cal is NOT a cannon. The last thing we want to do is give the other side more material to work with. The .50cal is a small arm; it just happens to be the big daddy of small arms.