Oh, even long after Facebook has turned sour as a company there have still been very good things running on top of Facebook as infrastructure for linking up disconnected local groups and individuals with shared interests.

But eventually they burnt so much goodwill trying to justify their stock valuation that at least were I am, all those informal groups have moved away from Facebook. Some managed to substitute the infrastructure quite well, some suffer quite noticeably. But none of them would consider going back. And openness to newcomers, discoverability, that has all suffered quite considerably.