Censorship imposed on one sector of society by another is an act of the first group's taking away freedoms that belong to the second group, regardless of the first group's intent.
Censorship is perpetrated by persons, organizations, committees who have seen, heard, read information they don't like or approve of, and so set a standard for others. While anyone is free to share an opinion, including cautionary warnings, I resent anyone else making such a decision in my behalf, deciding what it is that they know about that I should not. I'm capable of making such decisions for myself, and I believe the standard I set for myself will likely be higher than the one being set for me by self-appointed watchdogs.
The overriding point is that someone else has seen something and has decided that I (and others) should not.
The tradeoff for freedom of access is the risk of exposing oneself to that which may be overwhelmingly difficult to avoid influencing us negatively. If censors prevent (for instance) child pornography from appearing on the Internet, which they try but are unable to do, then I will never see it; this is fine in itself, because I hope never to have that horrible experience. If such material is present — and it is — there is always a chance one might stumble across some in complete innocence.
The world would be a much better place if people would behave themselves and not propagate information that is repugnant; but laws that limit free choice by individuals are untenable, repugnant in their own way. In contrast, if I apply sieves (literal or abstract) to my own environment, whether by leaving the TV off, not going to the movies, being discreetly selective about what I choose to read, avoiding likely trouble spots, enabling restrictive options in Google searches, adding powerful filters to my incoming email so that spam and messages from known jerks are blasted automatically to the iconoclastic infindebulum, all of which I actually do, it's my choice and right and even my moral obligation to do so. Just because badness exists does not mean that I must encounter and experience it first hand. But I cannot exercise my moral prerogative or righteous indignation toward what is bad if someone else has prevented me from doing so.