The main #Jitsi public instance https://meet.jit.si is now requiring logging in with a Google, Facebook or GitHub account in order to create new rooms. https://jitsi.org/blog/authentication-on-meet-jit-si/
Apparently they feel that there was too much abuse of their terms of service, but they do not give any details at all.
@eighthave @guardianproject quite a variety of things according to various users in the discourse community forum (https://community.jitsi.org/t/authentication-on-meet-jit-si/125922/6).