David Friedman, son of legendary economist Milton Friedman, has a blog.(feed) He does not post very frequently, but they are usually very thoughtful. I think it is fair to label him a libertarian anarchist, but that really does not say much. I was introduced to him originally through reading his book "The Machinery of Freedom" which imagines how an anarcho-libertarian society could be possible. Though it is not reality based in my view, it is thought provoking. He is not afraid to question anything. This recent post well illustates the type of thinker he is. His questions and ideas have very important social relevance and should not be seen merely as "on the fringe." I admire too the way this established author is composing a modern text.