The more effective way to control would be ensure that these designs (3D Printable Gun designs) are not available online. Few of the websites have already stopped publishing these designs, but unfortunately there are quite a few unauthorized sources still persists..By the way, one can view the Yourstory.com coverage of Altem Technologies
http://yourstory.com/2014/12/altem-technologies-stratasys-dassault-systemes/