More over, the printers required to do this are very expensive. His 'tiny' one is still over 20K USD. You try to do this with a standard FDM/FFF printer and it will blow up in your hands, possibly taking part of said hands with it. Additionally, a 'zip' gun can be made for less than 5 dollars worth of stuff at a hardware store. The freak out over 3d-printed guns is simply because people don't understand technology. When Glock handguns were first released in the US most areas made them illegal because someone said they were all plastic and didn't show up on a metal detector or x-ray. None of those statements are true. People focus on things that look or sound scary and not on actual fact or realistic possibility.