The administrators of popular mastodon instances share "block lists" manually. That's the level of coordination. Shared lists: https://github.com/tootcafe/blo

The administrators of popular mastodon instances share "block lists" manually. That's the level of coordination. Shared lists: https://github.com/tootcafe/blocked-instances https://github.com/tootcafe/blocked-instances https://github.com/MastodonBlocklist/blocklist https://github.com/MastodonBlocklist/blocklist https://github.com/ticki/mastodon-blacklist https://github.com/ticki/mastodon-blacklist and others