Clay Shirky has written an excellent rebuttal of Jaron Lanier’s wrong-headed critique of collaborative peer production on the Internet: “Digital Maoism: The Hazards of the New Online Collectivism.” Shirky’s response is one of about a dozen just posted on Edge.org, which also published Lanier’s essay.
Shirky begins by taking down Lanier’s straw man, the cliché of the “hive mind,” or mob, that propels collective enterprises like Wikipedia: “…the target of the piece, the hive mind, is just a catchphrase, used by people who don’t understand how things like Wikipedia really work.”
He then explains how they work:

Wikipedia is best viewed as an engaged community that uses a large and growing number of regulatory mechanisms to manage a huge set of proposed edits. “Digital Maoism” specifically rejects that point of view, setting up a false contrast with open source projects like Linux, when in fact the motivations of contributors are much the same. With both systems, there are a huge number of casual contributors and a small number of dedicated maintainers, and in both systems part of the motivation comes from appreciation of knowledgeable peers rather than the general public. Contra Lanier, individual motivations in Wikipedia are not only alive and well, it would collapse without them.

(Worth reading in connection this is Shirky’s well-considered defense of Wkipedia’s new “semi-protection” measures, which some have decried as the death of the Wikipedia dream.)
I haven’t finished reading through all the Edge responses, but was particularly delighted by this one from Fernanda Viegas and Martin Wattenberg, creators of History Flow, a tool that visualizes the revision histories of Wikipedia articles. Building History Flow taught them how to read Wikipedia in a more sophisticated way, making sense of its various “arenas of context” — the “talk” pages and massive edit trails underlying every article. In their Edge note, Viegas and Wattenberg show off their superior reading skills by deconstructing the facile opening of Lanier’s essay, the story of his repeated, and ultimately futile, attempts to fix an innacuracy in his Wikipediated biography.

Here’s a magic trick for you: Go to a long or controversial Wikipedia page (say, “Jaron Lanier”). Click on the tab marked “discussion” at the top. Abracadabra: context!
These efforts can also be seen through another arena of context: Wikipedia’s visible, trackable edit history. The reverts that erased Lanier’s own edits show this process in action. Clicking on the “history” tab of the article shows that a reader — identified only by an anonymous IP address — inserted a series of increasingly frustrated complaints into the body of the article. Although the remarks did include statements like “This is Jaron — really,” another reader evidently decided the anonymous editor was more likely to be a vandal than the real Jaron. While Wikipedia failed this Jaron Lanier Turing test, it was seemingly set up for failure: would he expect the editors of Britannica to take corrections from a random hotmail.com email address? What he didn’t provide, ironically, was the context and identity that Wikipedia thrives on. A meaningful user name, or simply comments on the talk page, might have saved his edits from the axe.

Another respondent, Dan Gillmor, makes a nice meta-comment on the discussion:

The collected thoughts from people responding to Jaron Lanier’s essay are not a hive mind, but they’ve done a better job of dissecting his provocative essay than any one of us could have done. Which is precisely the point.