Twitter communities is a similar idea I had a while ago. The ability to create invite only super-hashtag. Only people invited to the hashtag can reply but ever

Twitter communities is a similar idea I had a while ago. The ability to create invite only super-hashtag. Only people invited to the hashtag can reply but everyone can read. It seems to solve many of the current Twitter problems (apart from the whole failing to ban Nazis thing) but does create extra ones around community management of who gets to make invites/kick people from the community has tags