If he's become actively hostile to libertarianism, then this is a reverse from his originial position put forth here:

That leaves libertarians. Now, I love libertarians to death. My CPU practically has a permanent open socket to the Mises Institute. In my opinion, anyone who has intentionally chosen to remain ignorant of libertarian (and, in particular, Misesian-Rothbardian) thought, in an era when a couple of mouse clicks will feed you enough high-test libertarianism to drown a moose, is not an intellectually serious person. Furthermore, I am a computer programmer who has read far too much science fiction - two major risk factors for libertarianism. So I could just say, "read Rothbard," and call it a day.

On the other hand, it is hard to avoid noticing two basic facts about the universe. One is that libertarianism is an extremely obvious idea. The other is that it has never been successfully implemented.

This does not prove anything. But what it suggests is that libertarianism is, as its detractors are always quick to claim, an essentially impractical ideology. I would love to live in a libertarian society. The question is: is there a path from here to there? And if we get there, will we stay there? If your answer to both questions is obviously "yes," perhaps your definition of "obvious" is not the same as mine.