Of course, once the basic idea is out, motivated hobbyists will continue to trade the data files. As the article notes:
Even if possession/exchange of these data files is made explicitly illegal, there will still be an illicit underground "market" (as there is for pirated software, etc.)In response to Makerbot’s crackdown, Defense Distributed founder Cody Wilson wrote to me in an email, saying that the group plans to create its own site for hosting “fugitive” 3D printable gun files “in the next few hours.”
Neither Wilson believes that neither Makerbot’s purge of gun parts nor the outcry over the Newtown shooting has hampered Defense Distributed’s initiative. “The Internet routes around censorship,” he writes. “The project becomes more vital.”