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.
It's been answered further below. Yeah it's that one bloke who did it at https://lemmy.dbzer0.com/u/db0 . The projects also open source though, so anyone can run their own Overseer Control server, with their own chain of trust whitelist. I suspect many whitelists will pop up as the fediverse evolves.