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.
Is it possible to require an authentication app or something to make an account? Require a specific score on a flash game like snake? Or is that stupid? I don't know, I'm not a dev ¯_(ツ)_/¯
Apart from a lot of problems, some of this stuff is exclusive.