tburkhol , 1 year ago

In a federated system, users on Alice can see and post into communities hosted on Bob, eg alice/c/funplace@bob. When Meta tries to join, Alice chooses not to federate - avoid giving meta free content, protect its users from ‘bad’ meta communities, preemptively block toxic meta users, whatever - but Bob does federate. Alice users can’t see meta/c/advertising, there’s no way to subscribe to Alice/c/advertising@meta. Both Alice and Meta users can see Bob/c/funplace, and so alice users can see anything that meta users post there and meta ‘gets’ any content that alice users contribute. Bob effectively acts like a tunnel between alice and meta users.