I would envision something like “receipts” for federation and blocking.

From my understanding, activity stream objects (ie posts, comments) are cryptographically signed by their emitting instance. This means ban-worthy comments and defederation-prompting behaviour can be exhibited and “proven”, in a sense, not to have been falsified. In turn we could cultivate an expectation that blocklists provide receipts. Currently, many that I see are just a list instance domains or usernames, without no concrete examples of what they did to merit their bans. This has led to a certain amount of concern-trolling imo, and I’ve seen accusations and counter-accusations of racism and queer phobia between fedi instances and their admins that should (again, imo) be capable of finding common ground yet no one ever shows the offending material or behavior, they just describe it as warranting the blocklist.

The instance my mastodon account is based on, for example, defeds with fosstodon, and I can’t help but feel that a certain number of people I see on that instance would migrate elsewhere if they were aware of the current state of things, yet I myself can only parrot the vague accusations of bigotry given by my instance’s admins - all to easy for them to not “see the problem” in their day-to-day if they’re instance’s admins are remotely competent. I’m reminded of an article that came out like a week or two after charlie kirk’s death reflecting on how the author’s neighbor was blissfully unaware of all the awful things that man had said and done, and viewed him as a “family man”, because of how their social media experience had curated that exposure of him for her.

Rumours and hearsay are not a good foundation for exclusion, and if there’s no transparency in delegation of exclusion, then we won’t make meaningful differences compared to centralized, authoritarian, private social networks.