I think a key point is how important are social networks for society and what are the minimal functions they need to provide (or to abstain from) and how much legitimacy (and social support) is there to either regulate them far more extensively or recreate them from scratch in different modalities (say a large scale publicly, that is tax-funded, social network operated by a non-profit entity). I am trying to think of what already existing social institution is the closest analogy to digital social network platforms: roads? Public space? The (traditional) media? The educational system? Of course before doing something more radical, one could try first to fix the biggest problems with the biggest players in the market first (again). If we had large regulatory power over facebook (and given they don't develop a wider enlightened self-interest and social responsibility), how would we try to fix it!?
