A group of Senate Democrats is urging leading technology companies to ensure that the publication of 3-D gun printing materials, which violate their terms of service, is not allowed on their platforms.

Letters were sent, detailing concerns, to Twitter followers. Similar letters were sent to Facebook, Microsoft, Craigslist, Google, Reddit, and Yahoo.

Recently, a company called Defense Distributed announced that it would publish over the internet the blueprints for 3-D printable firearms, in the form of Computer Aided Design (CAD) files.

The CAD files would allow users from all over the world to automate production of a gun using a 3-D printer.

 “While a district court recently issued a temporary restraining order to prevent the online publication of these CAD files, the order was just temporary,” the letters say. “Moreover, there are already reports that thousands of such CAD files have already been downloaded by individuals, who can now disseminate the files privately or publicly on a variety of forums. That is deeply troubling.”  

“We appreciate that your company, like other social media companies, has terms of service that allow Twitter to remove content like 3-D gun designs from its platforms,” the Senators add.

Twitter’s Terms of Service, for example, inform users that: “We reserve the right to remove Content that violates the User Agreement, including for example, copyright or trademark violations, impersonation, unlawful conduct, or harassment … You may not use our service for any unlawful purposes or in furtherance of illegal activities.”

Twitter also “prohibits the promotion of weapons and weapon accessories globally. Examples of weapons and weapon accessories include: guns, including airsoft guns, air guns, blow guns, paintball guns, antique guns, replica guns, and imitation guns, gun parts, and accessories.”

“Based on your own terms of service, we urge you to proactively prevent the online dissemination of these dangerous 3-D designs across all of your platforms. Doing so will make all of our communities safer,” the letters say.

Among those signing the letters are: Sens Dianne Feinstein (D-Calif.), Bill Nelson (D-Fla.), Bob Menendez (D-N.J.), Richard Blumenthal (D-Conn.), and Ed Markey (D-Mass.).