This is a promotional video from the guys who make the black box you see sitting on the table in this video. This black box is a minature, self-contained, 3-D milling machine. It sounds like they made it for the sole purpose of machining receivers for AR-15 rifles. On the other hand, it looks like it could be used for any other project where you need a small milling machine. I'm intrigued because it looks like what these guys are doing it totally illegal, though appearances can be deceiving. The BATF has their rules on what constitutes a gun, and I'm pretty sure one of those rules is that the part in question has to be operable, and it wouldn't take much to make any gun inoperable. A hole drilled in the wrong spot, or the wrong size, or some little tab missing, and the thing won't hold together much less fire.
The whole argument about guns seem to be based on the premise that controlling guns will reduce gun violence. I am pretty sure that's a lost cause. However, as long as there is a sizable portion of the population that believes it, then it is unlikely anything will be done about the root cause of much of the violence, and that is the war on drugs. As long as heroin is illegal, guns are going to be the go to method of resolving business disputes in the drug trafficking industry.
The other problem I have with gun control efforts is that some of the worst massacres in history were committed against people who didn't have any guns. Now it might be that in wars, more soldiers, i.e. people with guns, get killed than civilians, that is, people without guns, but at least if you have a gun you can shoot back. You may still end up dead but at least you have a chance to make the bastards pay for it.