Today I found two discussions interesting and possibly salutory for social networks. "danah boyd on MyFriends, MySpace", a Berkman Luncheon Series discussion podcast, and a post on Stephen Downes OL Daily, "Anatomy of a Community Meltdown".
Boyd gives an excellent concise review of the history, rise and fall of a few key social network sites principally Friendster, MySpace and FaceBook. Downes links to a "... good object lesson in how an online community can be seriously disrupted." The common inferences that I draw are that social networks - call them communities if you will - can never be controlled (unless there are big carrots and even bigger sticks). Consent, consensus and co-operation are not even guarantors of success, though without these the network will degrade rapidly. Continuous growth is probably not a good thing; people have tolerance only for a few publics. Disruption may overwhelm even the best intentioned community.
Positive lessons:
- community opinion formers need to model the behaviour they would have practiced in the community, but this is no guarantee of success
- There needs to be some inclusive exclusivity: we do this; you can join us.
- sustainable development does not mean unlimited growth; development may even mean shrinking scope, numbers, activities. "Development" is highly contextualised and does not have one model
- disruption needs to be met with good will; and even then it may not be possible to channel it creatively.

