Andrew Keen's book, The Cult of the Amateur, has attracted a lot of incoming missiles. Last month, I linked to critiques by Clay Shirky and David Weinberger. Michael "Mr. Attention" Goldhaber has just published Part I of a response to the book on his weblog he's titled, The Cult of the Professional. I'll link to Part II when he posts it. Link: Michael H. Goldhaber.
Updated 31 August 2007:
Here's Part II, Social Networking vs. Gulags. --Dennis