So, the instance I joined Lemmy on last week largely to participate here defederated from lemmy.world an hour ago. It’s early post-Reddit days, which is the only reason I’m posting a general tech tip in /r/!austin, but it’s a previously impossible inconvenience that isn’t theoretical. Choose wisely or start your collection of alts early!
The admins have been very open about the whole thing. It basically revolves around the open signup policy (my other instance requires a short essay and decides on admission because of the tone they want to see) and the fact that a few bad actors were harassing admins, mods and users. The currently available option that addresses this is full defederation; the decision is being sold as temporary until finer controls are available.