A New York City attorney is suing the U.S. State Department over a proposed change to the International Traffic in Arms Regulations (ITAR). The change pertains to how the regulations define “public domain,” and, if implemented, could result in what the attorney characterizes as an unconstitutional prior restraint on free speech.

Under the ITAR, items described on the United States Munitions List are “defense articles.” So is information, or “technical data,” required to make, operate, repair, test, maintain, or modify defense articles. Barring a handful of exceptions, anyone who wants to export a defense article, including technical data, is required to first obtain an export license from the State Department’s Directorate of Defense Trade Controls (DDTC). One exception to that requirement is if information that would otherwise be “technical data” is available in the public domain.

In recent history, the ITAR’s “public domain” has encompassed information that is “generally accessible or available to the public” by way of select media. Newsstands and bookstores, open subscriptions, libraries, fundamental research at universities – the ITAR currently recognize all of these and more as constituting their version of the public domain. Notably absent from the list: unrestricted access via the Internet. Contrary to persistent and pernicious rumor, simply publishing technical data on the Internet does not automatically place it in the public domain, and can in fact cause a cascade of ITAR violations as foreign nationals living both in the U.S. and abroad access it.

In June of this year, DDTC published a notice of proposed rulemaking that categorically drives that point home. The notice (80 Fed. Reg. 31,525) explains that the new definition of “public domain” codifies an alleged preexisting requirement that anyone wishing to make technical data readily available to all via any format must first obtain permission to do so from the U.S. government. This apparently was news to the Manhattan attorney, who promptly filed suit just before Halloween in Manhattan district court for violations of his First and Fifth Amendment rights.

The lawyer argues that DDTC’s position imposes an unconstitutional prior restraint on his ability to speak freely with clients and the U.S. public on ITAR matters. This is similar to the claim made by Texas-based nonprofit Defense Distributed, which in 2013 published blueprints for a 3-D printed pistol on its website. DDTC ordered the entity to take the drawings down, which (100,000 downloads later) it did. But after two years of languishing in enforcement limbo, Defense Distributed decided to sue the agency on the same constitutional grounds as the aggrieved attorney. That makes two fora in which the judiciary will have the opportunity to weigh in on the appropriate balance between the public’s interests in national security and free speech. Stay tuned for updates as the cases wind their way to resolutions.