Freedom of speech needs to be restricted to protect freedom of speech.
This apparent paradoxical statement is well-founded in philosophy, but it is the cause of much confusion in online debates. Quite regularly, any kind of moderation activity in comment sections or other discussion spaces is likened to censorship, with the argument that the basic human right of freedom of speech needs to be protected.
While it is possible to silence all dissent using moderation, most of the time when freedom of speech is invoked, it is done in the misguided assumption that ultimate freedom is the goal.
It can not be.