Please. Captcha by default. Email domain filters. Auto-block federation from servers that don't respect. By default. Urgent.
And yes, to refute some comments, this publication is being upvoted by bots. A single computer was needed, not "thousands of dollars" spent.
HackerNews does something similar where new users don't have the ability to down vote until they have earned enough upvotes from other users.
We could extend that, and literally not allow upvotes to properly register if the user is too new. The vote would still show on the comment/post, but the ranking of the comment/post will only be influenced by seasoned users. That way, users could scroll down a thread, see a very highly upvoted comment bang in the middle, and think for themselves "huh, probably bots".
Very hierarchical solution, heavily reliant on the mods not playing favourites or having their own agenda.
As any solution to this sort of problem should be, IMO.
If the mods suck, then go make another community. If enough of the mods are good, they can be a huge part of the solution. I'm envisioning this:
Transparency keeps the mods honest, or at least allows users in the community to name and shame bad mods.
Some automated tools to help mods out are always welcome.