Censorship, like gun control, is a slippery slope. 

Via the Washington Post: 

Last week, a federal judge in Seattle effectively blocked a pro-gun group from publishing computer-code blueprints that could be used to make guns with 3-D printers — at least until further hearings can be held. The restraining order will please lawmakers and gun-control advocates who have been up in arms following the Trump administration’s decision to let the group publish the instructions.

But those who oppose these weapons shouldn’t be celebrating. A government ban on publishing such blueprints is going to be difficult to sustain — and that’s probably as it should be. As one court put it in 2001: “Communication does not lose constitutional protection as ‘speech’ simply because it is expressed in the language of computer code.”...

Skepticism that government officials can accurately balance the good and ill effects of speech  is properly reflected in the Supreme Court’s free speech rulings. While the court has never addressed what protection is reserved for potentially harmful instructional speech, it has only recognized a few narrow categories of speech that can be restricted on the basis of harm, such as inciting immediate acts of violence.

Moreover, the court recently said it will refuse to recognize any new proscribable categories of speech unless it can be proved they never enjoyed First Amendment protection. This effectively means that the government would likely face an extremely heavy burden of showing that a ban on instructions for 3-D-printed guns was necessary to avert harm.

Read more here.