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.
Not only that, also show users when comments in any community are made by users from an instance that your instance defederated.
Because you(instance A) may very well only be able to see half of the comments in a thread of a community of instance B because half of them were made by users of instance C which instance A defederated.
Right now the comments just don't get copied to your instance at all, which also leads to followup comments not being visible even if they are not from defederated instances.
Instead I'd like everything to be copied and then flagged based on defederations. Just don't show the original content and instead show a hint that a comment can't be seen because of defederation would be enough.
At least that way we know that we're missing something.
Because simply not showing it also leads to confusion why you see less comments than other users on another instance.
And this goes both ways. The user from the other instance(who can still see your comment because his instance didn't defederate yours) should also see that I'm from an instance that defederated his instance directly by looking at my post before commenting, maybe in form of a symbol or a note next to my username, so that he knows it doesn't make any sense to comment on my post.