I recently learned that voting on lemmy is not anonymous. Anyone can get information about who has upvoted and downvoted a post or comment.
In combination with your IP, this is a massive privacy (maybe even physical security) risk. Also, people can target you for your votes.
Sadly, this is something where I would prefer Reddit over Lemmy. Big tech scrapes data from both places anyways, at least Reddit is safe.
Important to note here, too, is that ip addresses of users arent synced across instances.
This is only a problem for people who care about the reputation of their user account - which is something people should be rotating out anyway if they care about their privacy.