A newly dispatched memo from the Department of Homeland Security warns that preventing the creation of 3D-printed guns could be an extremely challenging if not impossible endeavor. "Significant advances in three-dimensional (3D) printing capabilities, availability of free digital 3D printer files for firearms components, and difficulty regulating file sharing may present public safety risks from unqualified gun seekers who obtain or manufacture 3D printed guns" reads the document, reportedly obtained by Fox News. The bulletin goes so far as to mention the "Liberator" 3D gun, plans for which were distributed on the web for a brief time. "Limiting access may be impossible" the memo says. Lawmakers have been pushing to create legislation barring 3D-printed guns, but stopping the spread of design files is just one of the challenges complicating such a ban.

The memo goes on to discuss a potential nightmare scenario; the removal of any metallic parts from 3D guns that would make them difficult to detect using security tools. "Though it is prohibited by federal law, manufacturers may deliberately omit the unnecessary metal insert, leaving only a small nail and ammunition as the sole metal component. Future designs could further reduce or eliminate metal entirely," it reads. Of course, printing a 3D gun remains a fairly complex (and costly) process, likely one of the only things giving lawmakers peace of mind at the moment.