The best part of the fediverse is that anyone can run their own server. The downside of this is that anyone can easily create hordes of fake accounts, as I will now demonstrate.
Fighting fake accounts is hard and most implementations do not currently have an effective way of filtering out fake accounts. I’m sure that the developers will step in if this becomes a bigger problem. Until then, remember that votes are just a number.
IMO, likes need to be handled with supreme prejudice by the Lemmy software. A lot of thought needs to go into this. There are so many cases where the software could reject a likely fake like that would have near zero chance of rejecting valid likes. Putting this policing on instance admins is a recipe for failure.