Earlier quoted context omitted.
The government can't exactly ban chemistry textbooks, can it? Anyway, for this type of censorship to be effective to prevent dissemination of knowledge, it would need to happen before distribution, and prior restraint is generally considered unconstitutional in the US, except in matters of national security. National security could likely include planned troop movements and nuclear weapons manufacturing procedures (a…
There's a pretty big difference between a chemistry textbook on the one hand, and a step by step layman's guide on how to make a bomb, avoid detection and so on on the other. And then of course beyond that you can go into progressively more dangerous weapons. Would a guide to building IED's with shaped explosives fall under the protections, for instance? I was just watching a documentary yesterday about Iran taught t…
If your society is held together by a lack of available knowledge on how to blow stuff up (or take other dangerous actions), I don't expect it will be held together for very long. Motivated people can figure this out pretty quickly.