From an outsider: What happened?

Please forgive me if this topic, or this forum, isn’t the place for an outsider to butt in and ask Stupid Questions, but what exactly happened to SBC recently? I regret that my ear is about as far from the ground as possible as concerts the Fediverse or any of its member instances; the first I heard of SBC was shortly after said happening, but that “shortly” was long enough (about two days, IIRC) that all I can see is its aftermath.