Privacy/anonymity is the only cure for the rampant destruction of individual rights that's happening throughout the world as spying tech advances(Hello nsa, google etc...) both in economic and social matters.
Im all for privacy and anonymity, but there's always a downside. Who would pay for the welfare for the people that really need it (because some do really need it). If nothing is public anymore, how in hell would that be deal with? I don't see it would work in a 100% anonymous individual society.