This only further proves the point that up/down votes are useless here. I can have an account on each federated instance (just one, so not to possibly run afoul any local server rules) and have a script to just run through all of them to downvote something. Could easily be a hundred votes at my singular whim.

If the names of the accounts are not particularly linked... you wouldn't really be able to tell that there was much vote manipulation either.