Richard A. Posner (Federal Judge and blogger):

The charge by mainstream journalists that blogging lacks checks and balances is obtuse. The blogosphere has more checks and balances than the conventional media; only they are different. The model is Friedrich Hayek’s classic analysis of how the economic market pools enormous quantities of information efficiently despite its decentralized character, its lack of a master coordinator or regulator, and the very limited knowledge possessed by each of its participants.
In effect, the blogosphere is a collective enterprise – not 12 million separate enterprises, but one enterprise with 12 million reporters, feature writers and editorialists, yet with almost no costs. It’s as if The Associated Press or Reuters had millions of reporters, many of them experts, all working with no salary for free newspapers that carried no advertising

Great stuff. More on Richard Posner.