The governing authorities steer the public to adhere to guidelines that stop mass groups going on a chaotic rampage against the establishment. That comes under the law of the land.
Therefore, anarchy and a shaking up of the rule book is fine and dandy, but bringing back my post into context, when it comes to a piece of literature blatantly advocating violence perpetrated against society and endangering the innocent, it stands to reason to fully support the "censoring" of such materials, in an attempt to stop it falling into the wrong pair of hands.
Censorship per se is full of grey areas and divides opinion, as is seen here.