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.
Sure there’s individuals doing it already.
It only becomes a problem when a medium starts reaching a significant audience, then interventions are needed, like when Reddit boomed. Then the US regime put their puppet there.
Same as they did with Facebook,etc…
With Lemmy being different I suppose they will have to find new ways or just massively use bots or paid trolls.