The
problem isn’t open vs closed; the problem is that Facebook
have built a very effective way of creating communities of
interest like this, and then closed it, because that’s
profitable.
I must say that several relevant online and offline (or both)
communities of interest existed much more time before facebook and
other social networks. An example is this mailing list :)))
The real problem I see is that cyber-social life is moving to some
closed platforms governed by a small number of big players.