Defense Distributed's design for the Liberator pistol, the plastic handgun that can be almost entirely fabricated by a 3D printer, has been, at least for now, stricken from the organization's website by order of the US State Department. While some have decried the move as politically motivated, the reason for the takedown is straightforward—Defense Distributed, while working to comply with US firearms regulations, failed to register with the State Department to cover export controls. By posting the designs for the Liberator and other weapons technology to DEFCAD.org, Defense Distributed was in effect exporting those weapons without a license.

Defense Distributed posted a note on the download page for the Liberator: "This file has been removed from public access at the request of the US Department of Defense Trade Controls. Until further notice, the United States government claims control of the information," followed by an image of the seal of the US State Department. The same notice has been posted for a number of other designs on the site, including a design for a high explosive anti-tank shell, a silencer, and other accessories and components for firearms.

The Defense Department is not involved in the action. In a letter to Defense Distributed that was subsequently posted on Slashdot, an official of the State Department's Office of Defense Trade Controls Compliance, Enforcement Division informed the organization that the Liberator and a list of other weapon-related designs on the DEFCAD.org 3D printing design site were potentially in violation of International Traffic in Arms Regulations (ITAR). Semi-automatic and non-automatic firearms up to .50 caliber are considered "munitions" under the Arms Export Control Act.

A State Department official confirmed that a letter had been sent to Defense Distributed. "As a matter of policy, we do not comment on individual ongoing compliance matters," the official told Ars. "However, we can confirm that the Department has been in communication with the company. Under the Arms Export Control Act, any person who engages in the United States in the business of manufacturing or exporting defense articles, furnishing defense services, or engages in arms brokering covered by the International Traffic in Arms Regulations is required to register with the State Department (via the Directorate of Defense Trade Controls). Separate from this registration requirement, additional licenses are needed for exports of defense articles in most cases."

Even the exchange of information about systems related to technologies regarded as defense articles are tightly regulated by the State Department because of the potential threat exported weapons and defense-related items pose to both national security and "peace and security of the broader international community," the official said.

That tight regulation has posed problems for other Internet liberty advocates who have run afoul of the Arms Export Control Act. In the 1990s, encryption technology with keys larger than 40 bits was considered a "munition"—which put PGP encryption creator Phillip Zimmerman in legal trouble when he made it freely available online. The outcry led to the moving of "dual use" encryption technology off the State Department's list and put it under the regulations of the Department of Commerce.

But just as with PGP, the State Department order won't put the genie back in the bottle. The Liberator and the other items on the list in the State Department letter have already been heavily downloaded and are being actively shared via torrents.