where does CSAM or revenge porn fit in with anti-censorship?
Freedom of Expression does NOT cover things that cause tangible harm to specific people.
Everyone has innate human rights. Freedom of Expression is one of them, but it is not the only one. People also have rights to bodily autonomy, privacy, dignity, safety, and to not be sexually exploited.
Child Sexual Abuse Material ("CSAM" - this is now the preferred term for "child pornography") may technically be a form of "expression" in the most literal sense - but it is a form that is the documented product of the sexual abuse of a real child, and its circulation continues that abuse.
Likewise, Non-Consensual Intimate Imagery ("NCII" - this is now the preferred term for "revenge porn") is the non-consensual distribution of intimate material in a way that directly violates a specific person’s privacy, dignity, and safety.
So I really don't think this is a case of making some prudish exception to anti-censorship principles. It's a case of recognizing that one person’s claimed "expression" cannot include the right to violate another person’s human rights.
And, as a side note, that is also why FICTIONAL depictions of abuse, or even ugly works that seem to romanticize or encourage abuse, fall into a very different category.
Those works may be highly disturbing, exploitative, disgusting, or morally rotten, but they are NOT actually abusing a specific real person in the way CSAM and NCII are - the harm there is direct, concrete, and inseparable from the material itself.
With fiction, the argument is usually vague and indirect: some third party might consume it, be influenced by it, and then do something harmful later. That kind of causal chain is speculative, hard to prove, based on the actions of another person with their own free will, and potentially limitless once you start to expand on it. If you make that the standard for censorship, then practically any book, film, fantasy, or artwork could potentially end up suppressed on the theory that it might negatively affect someone somewhere.
Freedom of expression does protect idiotic ideas, disgusting art, fantasies, and highly offensive speech. But it does not include a right to sexually exploit, expose, or abuse a real person and then call the evidence "speech."