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.
Votes being public is a lemmy specific issue
But they aren’t tied to any public information that relates back to you, unless you voluntarily make this information public yourself. You have the exact same “privacy (maybe even physical security)” risk, like when you use reddit. Just that with reddit you have to trust reddit to use the platform, while in the Fediverse you only have to choose one instance to trust.
Votes are public here and not on Reddit. Someone who doesn’t like a downvote can go on a witch-hunt, something which is happening to my comments right now.