To be honest, I think this argument is FUD as well. There are some Russian accounts and there is disinformation, but this isn't the core of polarization in western democracies and Europe in particualr. And reigning in free speech is even poison in this situation, which is more complex than pointing your finger at bots.

In Europe freedom of speech is under threat from its own population, which is more and more driven by fear. This fear might not be unreasonable and has multiple sources, but it remains a bad basis for decision or policy making.

The fear is being heavily stoked by agitprop on social media.