The topic of discussion is how to prevent them from doing any harm, rather than which space crocodile is secretly controlling us with mind-control lasers, or whatever their lunacy-of-the-day may be. This is a win. They’re being exposed without giving them the satisfaction of censoring them. Freedom of speech does not mean freedom from consequences.
This is not high-school debate club. Anyone with a modicum of media litteracy knows you don’t give a platform to Russian shills, or anyone peddling any kind of similarly lunatic propaganda for that matter. If you want to know more, read their post history. The reason that you don’t do that is that the minute they get sufficient mindshare, they’ll be more than happy to bend the rules of civil discussion. We’re talking about people defending China and its censorship, after all.
And look, you’re more than welcome to criticize American imperialism and liberal hypocrisy. But shilling for authoritarian regimes is a red line any leftist worthy of the name should not cross.