This blog post by Ploum, who was part of the original XMPP efforts long ago, describes how Google killed one great federated service, which shows why the Fediverse must not give Meta the chance
2 points
how could we disallow them from joining?
easy, identify them, never allow them to federate, block them in your firewall. Their instances won’t be anonymous
1 point
Ok, but you can only do that if they already joined the fediverse. I replied to “the powers that be must never be allowed to join the fediverse”. It’s also questionable if everyone will block them.
2 points