This week marks the two-year anniversary since Cody Wilson, the inventor of the world’s first 3-D printable gun, received a letter from the State Department demanding that he remove the blueprints for his plastic-printed firearm from the internet. The alternative: face possible prosecution for violating regulations that forbid the international export of unapproved arms.

Now Wilson is challenging that letter. And in doing so, he’s picking a fight that could pit proponents of gun control and defenders of free speech against each other in an age when the line between a lethal weapon and a collection of bits is blurrier than ever before.

Wilson’s gun manufacturing advocacy group Defense Distributed, along with the gun rights group the Second Amendment Foundation, on Wednesday filed a lawsuit against the State Department and several of its officials, including Secretary of State John Kerry. In their complaint, they claim that a State Department agency called the Directorate of Defense Trade Controls (DDTC) violated their first amendment right to free speech by telling Defense Distributed that it couldn’t publish a 3-D printable file for its one-shot plastic pistol known as the Liberator, along with a collection of other printable gun parts, on its website.

By posting a file online, the DDTC claimed Defense Distributed had potentially violated arms export controls—just as if it had shipped AR-15s to Mexico.

In its 2013 letter to Defense Distributed, the DDTC cited a long-controversial set of regulations known as the International Traffic in Arms Regulations (ITAR), which controls whether and how Americans can sell weapons beyond U.S. borders. By merely posting a 3-D-printable file to a website, in other words, the DDTC claimed Defense Distributed had potentially violated arms export controls—just as if it had shipped a crate of AR-15s to, say, Mexico. But the group’s lawsuit now argues that whether or not the Liberator is a weapon, its blueprints are “speech, ” and that Americans’ freedom of speech is protected online—even when that speech can be used to make a gun with just a few clicks.

“The internet is available worldwide, so posting something on the internet is deemed an export, and to [the State Department] this justifies imposing a prior restraint on internet speech,” says Alan Gura, the lawyer leading the lawsuit, using the legal term “prior restraint” to mean censorship of speech before it’s published. “That’s a vast, unchecked seizure of power over speech that’s…not authorized by our constitution.”

“If code is speech, the constitutional contradictions are evident…So what if this code is a gun?” asks Cody Wilson, Defense Distributed’s founder, a radical libertarian who dropped out of the University of Texas law school to run the firearms access group. “Nothing can possibly stand in the way of this being disseminated to the people, and yet they insist on maintaining the power to do so.”

The Return of the Crypto Wars

ITAR already has a long history of being used to threaten Americans who publish controversial code. In the 1990s, the same regulations were used to threaten cryptographers with prosecution for posting online the first freely available strong encryption tools. Under ITAR regulations, a piece of uncrackable crypto software like PGP was considered a military munition. PGP inventor Phil Zimmermann was even investigated by the Department of Justice for three years at the height of what has come to be known as the Crypto Wars.

The Justice Department eventually dropped that investigation without an indictment or an explanation. But before it did, the cryptographer Dan Bernstein sued the State Department, arguing that ITAR was an unconstitutional violation of the First Amendment. He won. But while government lawyers appealed the case, control of encryption software exports was moved from the State Department to the Commerce Department and then protected by a new exception, preventing Bernstein vs. the United States from proving ITAR unconstitutional on first amendment grounds.

Wilson’s lawsuit, two decades later, is taking another shot at ITAR with that same first amendment argument. Only this time the fight isn’t over code erroneously labeled as a weapon. The code in question actually is a weapon.

“This is a second bite at the apple,” says Wilson. “It’s very much the spiritual successor to Bernstein.”

Not every lawyer is convinced that Defense Distributed’s free speech argument will be quite as successful as Bernstein’s. “The State Department’s takedown demand probably qualifies as a prior restraint, to which courts are incredibly hostile,” wrote intellectual property lawyer Ansel Halliburton in a guest article for Techcrunch after the State Department’s original letter to Defense Distributed. “But the ability to download a file, press ‘Print,’ and have gun parts come out could also tip some judges toward calling gun CAD files functional things and allowing the government to regulate them.”

Phil Zimmermann himself, who was threatened with prosecution for ITAR violations in 1993, says he supports Defense Distributed’s lawsuit and believes the free speech argument he made then should apply just as much to gun code as it did to crypto code. “I see this as very similar to the PGP situation,” he says. “I’m not a gun nut. I don’t own a gun. But publishing a blueprint for a gun should not be illegal.”

The Second and Fifth Amendments Are Getting Play, Too

Defense Distributed’s legal team on the case includes Alan Gura, a litigator who has successfully argued two second amendment cases before the Supreme Court, and ITAR-specialist attorney Matthew Goldstein. Wilson says that he’s been receiving additional legal advice from the civil liberties group the Electronic Frontier Foundation (EFF) since not long after receiving the State Department’s ITAR letter. The EFF declined WIRED’s request for comment.

In fact, that legal team is attacking the State Department with more than just the first amendment: Its complaint also cites the second amendment, arguing that by restricting Defense Distributed’s sharing of printable gun files the government denied the group’s members and followers the right to bear—and acquire—arms. And it questions the authority of the State Department to regulate the publication of technical data, a power it’s long assumed it had been granted by Congress under the Arms Export Control Act of 1976.

Defense Distributed is hitting the State Department with a fifth amendment argument, too. It claims that its staff had their right to “due process” violated. No government agency, it says, can hold the threat of prosecution over Defense Distributed’s head without even a decision on whether its publications are illegal or not—and without a time limit on when it must make that decision. Defense Distributed says it asked the DDTC for ITAR approval to publish the gun files after receiving its letter, and have waited two years without response.

The lawsuit seeks damages from the State Department for years of restricting Defense Distributed’s activities. But first, it seeks to have a judge place an injunction on the State Department that would prevent it from continuing to censor Defense Distributed’s files. If that injunction is granted, the group could immediately publish a slew of gun blueprints it’s developed over the last two years even before any resolution is reached in the lawsuit.

We’ve reached out to the State Department for comment on the lawsuit and will update when we hear back.

Of course, the State Department’s two years of invoking ITAR against Defense Distributed haven’t prevented its 3-D printable gun files from spreading across the web. Instead, a Streisand-Effect-like fear of government censorship helped spur more than 100,000 downloads of the Liberator blueprint in two days. By the time the file was removed from Defense Distributed’s websites, it had already appeared on the Pirate Bay and other bittorrent sites, where it’s become nearly impossible to erase. And in the years since, amateur gunsmiths on sites like FOSSCad and GrabCAD have continued to evolve the Liberator’s design and share their own blueprints for 3-D printable revolvers and rifles.

Technically, all of those sites likely violate ITAR too. But the proliferation of potentially ITAR-violating files across the internet shows just how absurd and futile the State Department’s task of policing that digital contraband has become, says Matthew Goldstein, the ITAR expert on Defense Distributed’s legal team.

“You just can’t do this. You can’t punish someone for speech just because someone believes that speech could be used for bad stuff…If you even just think about all the reposts, it’s a mess,” says Goldstein. “It’s like grabbing at particles of smoke.”

Here’s the full complaint from Defense Distributed:

Defense Distributed et al v. U.S. Dept. of State by crw4199