The Group Ban feature on the server side rolled out today. After tomorrow’s roll outs to the RC channels the server side of Group Ban will be complete. All regions in the main grid will have the feature.
This afternoon the Project Viewer appeared on the RC and Project Viewers page. See Project Group Ban 126.96.36.1990887. The release notes with some instructions for how to use the feature is here: GroupBan/188.8.131.520887 Release Notes.
For all practical purposes, we have group ban. Those wanting to ban people from their groups need to get the Project Viewer. Those being banned will be banned no matter which viewer they use. The ban actually happens server side. The Project Viewer is just needed to tell the server who is banned.