I think that the media, enthusiastically assisted by others who are captivated by their own privileged position of power and money, make up a lot of these stories. The constant meme regarding 3d printing of guns seems to me to be overblown hyperbole. Truth is that a plastic gun would be as useful as one fabbed out of wood. The simple fact is that guns don't work without ammo. Try 3d printing a nato round! (Sales of ammunition are at least as tightly controlled in the world that I inhabit as the guns needed to project them) All that is needed to make an operational rifle is a lathe, milling machine, some metal and a capable machinist. Hardly exotic.