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.
If you and several other accounts all upvoted each other from the same IP address, you’ll get a warning from reddit. If my wife ever found any of my comments in the wild, she would upvoted them. The third time she did it, we both got a warning about manipulating votes. They threatened to ban both of our accounts if we did it again.
But here, no one is going to check that.