A just/discriminating censorship is impossible

From Susan Sontag on Censorship and the Three Steps to Refuting Any Argument by Maria Popva. Quoting Susan Sontag:

The main techniques for refuting an argument:

Find the inconsistency
Find the counter-example
Find a wider context

Instance of (3):

I am against censorship. In all forms. Not just for the right of masterpieces— high art— to be scandalous.

But what about pornography (commercial)?
Find the wider context:
notion of voluptuousness à la Bataille?
But what about children? Not even for them? Horror comics, etc.
Why forbid them comics when they can read worse things in the newspapers any day. Napalm bombing in Vietnam, etc.

A just/ discriminating censorship is impossible.