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.
The only way to get rid of the bots is for moderators to pay attention.
That's like saying "My corporation doesn't need anti-virus! we have smart users!"
Defense in depth is the only philosophy that makes sense in this case imo.