Should it be permissible, both legally and ethically, for governments to censor material either in print or online that instructs how to commit violent crimes (e.g. "How to Make Plastic Explosives" or "How to Poison the Water Supply")? Are such materials really considered to be "Speech?" Many Western democratic societies allow hate speech, and incitement is only ever prosecuted if it calls for direct violence against a particular group or individual; instructional manuals need not call for violence against people or any action at all. But at the same time, people like Timothy McVeigh have carried out acts of mass violence by using such manuals.

The legal question varies from country to country, and with regard to the US there is a case to be made that the kinds of instructions you have in mind are speech and therefore protected by the First Amendment. Morally speaking, the case for considering it permissible to prohibit the publication of such instructions seems overwhelmingly strong. There is no legitimate public interest in having such information widely available, and there is a considerable danger to the public from such wide availability. So the public is better served if such publications are prohibited. Here it is important to formulate the prohibition narrowly and with some precision because a broad or vaguely worded statute can easily be used to criminalize or intimidate legitimate political opposition.

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