The State Department is forcing Defcad, known as the Pirate Bay of 3D printing, to remove its 3D-printable gun files, according to Defense Distributed, which runs the site.

According to a note atop the Defcad website: "Defcad files are being 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."

Defcad was announced at this year's SXSW. Its goal was to provide unfettered access to 3D printable firearms, as well as other designs that can be used to print anything from household tools to pharmaceuticals.

According to a letter from the State Department obtained by Forbes, distribution of the files might be in violation of International Traffic in Arms Regulations (ITAR).

Specifically, the agency is concerned about the blueprint for the "Liberator" handgun, which had its first successful test fire this week, as well as nine other 3D-printed gun files.

"Until the Department provides Defense Distributed with final [commodity jurisdiction] determinations, Defense Distributed should treat [those files] as ITAR-controlled," the letter said. "This means that all data should be removed from public access immediately."

The State Department did not immediately respond to a request for comment.

The announcement came after more than 100,000 people downloaded the blueprint for the Liberator 3D gun, according to Cody Wilson, the law student behind Defense Distributed and Defcad. PCMag spoke with Wilson earlier today prior to the Defcad takedown; for more, check out our interview.

In terms of the legality of 3D guns overall, the Undetectable Firearms Act outlaws the manufacture, import, selling, shipment, delivery, possession, transfer, or reception of any firearm that is not detectable by walk-through metal detectors, or has major components that do not generate an accurate image by airport X-ray machines.

Once the file is uploaded online, though, anyone can download and print the gun, sans serial number, background check, and other regulatory requirements. That's what has Rep. Steve Israel worried. The New York Democrat last week renewed his call for an extension of the ban on plastic firearms - set to expire in Dec. 2013 - including homemade magazines and receivers.

After today's Defcad news, Israel said in a statement that said "we still need to pass my legislation, the Undetectable Firearms Modernization Act, to give local law enforcement officials the tools they need to prosecute people who would make plastic firearms using the files that have already been downloaded 100,000."