If there's an imposed censorship, then it's not 100% free speech.
But I understand your point; even here, where we boast the freedom of speech, although the rules are basically common sense,  spam, plagiarism, body harm and so on get excluded/removed/banned.
Still, the more "exceptions" we add, the more harm we do on long term.

On the other hand, certain lying trolls can be easily ignored by those who no longer want to see its posts. (On the other hand, reporting for trolling can do longer term effects.)