What you may not know though is he recently announced that he will stop focusing his attention on copyright and related matters, and will instead work on corruption in the political system. He explains why in this video interview.
Listen to the interview - this is a fundamental KM issue - we have the knowledge - we understand the problems but we don't take action or we take the wrong action because the system is corrupt. Lessig thinks the solution lies in Commons-based peer production.
This is a man to watch carefully and to support. I am intrigued as to where this heading. As Lessig says in the interview if we are going to solve problems like global warming then we need to fix the "corruption" first.