Take this post for example: https://www.reddit.com/r/northernireland/comments/1ll6ocg/see_it_say_it_censored_kneecap_is_not_the_story/
Speaking from experience, people in Ireland are overwhelmingly pro-palestine.
There is this user in the comments: https://www.reddit.com/user/EntireCourage308/
Its a nearly year-old account, it started posting about a month ago, it made some innoculous posts, then pivoted to posting far-right misinformation in the r/northernireland subreddit.
There’s loads of other accounts just like it.
Even with it being federated I don’t see how Lemmy could be immune to astroturfing. I’m sure there’s some already going on. Lemmy just isn’t yet popular enough to be a major target. Instances can defederate from one another but it’s trivial to create a new account on a different instance and resume turfing. I suppose the openness of Lemmy’s logs, when compared to the closed-source centralized nature of reddit, could help suss out turfers though.
extreme versions political communities, instances are likely to get spammed, so reducing that would be defederating or blocking those instances. Lemmy will eventually have to come up with more anti-botting tools to combat this.