If you read enough, you just have to be wary of "Here Comes Everybody" and its ilk. If you're the sort of person thinking of reading Shirky's book, you've probably also read Larry Lessig (Code), Yochai Benkler (The Wealth of Networks, not to mention essays like "Coase's Penguin"), Shapiro and Varian (Information Rules), maybe Weinberger (Everything is Miscellaneous), and on and on. You've used the Wikipedia. You may well use Linux. You've learned about "the wisdom of the crowds" (Surowiecki). You've got "the long tail" in there somewhere too.
What does Shirky add to this cacaphony? He adds one important special case of all of the above: the Internet lets us form groups effortlessly. Now we can work together on projects that we wouldn't have known about otherwise. We can find other people for fun in the real (non-Internet) world. We can find people with remarkably obscure interests matching our own. Previously these would have taken far too much time and effort. And the payoff is far too low for any company to be interested in connecting, say, lovers of ancient Chinese art. What the Internet has given us is a set of tools that allow us to create and find these groups.
This comes with its downsides. For instance, at the same time that it becomes easier for me to find blogs devoted to 18th-century ship-in-a-bottle designs, it becomes easier for you to find backwoods militias. The example Shirky gives here is a web bulletin board devoted to encouraging anorexia among its teen members. (This was the only part of the book that actually horrified me.) In the real world, these sorts of groups succumb to social pressure and go into hiding. The web makes it possible for them to find one another; they are no longer alone.
Shirky only gives the briefest treatment of these groups, and seems generally in favor of them for the same reason that people favor free speech: it protects the speech we hate as well as the speech we support. I would have liked deeper coverage here. In a lot of senses, the Internet is making us reconsider the foundations of democracy: now we're face to face with the consequences of truly free speech; what do we do about it, if anything? Do we still stand by the free-speech absolutism that we clung to when it was more or less hypothetical? Shirky doesn't really touch on this.
He's quite often a techno-idealist, which is a stance he assumes professionally. As a technologist, he's convinced that the spread of cheap communications technologies will allow protesters to connect and topple ruling elites; he uses protests within Belarus as an example. He doesn't really follow this up with counterexamples: Great Firewall Of China, anyone? More to the point: politics will exist even after text messages amongst flashmobs are a faint memory. I'd have liked this book better had Shirky cowritten it with a political scientist.
Had Shirky dug into this a little more, the whole tone of his book would have changed. Had he scaled out his historical perspective, he might not be as optimistic either. I've been reading about the revolutionary potential of technology at least since I started using PGP; it was supposed to have been used by freedom fighters in the jungles of Burma. This strain continued through O'Reilly's publication of its collection of essays on P2P. Within there were essays on, say, FreeNet, which was explicitly designed to create a censorship-proof peer-to-peer network. Only the occasional voice was brave enough to ask whether FreeNet would even be permitted within a repressive regime. If Shirky were interested in convincing me that technology might topple existing power structures, he'd go ask how those freedom-fighters are doing.
Shirky's is a valuable point of view, but it's a point of view that I've heard too many times. Nowadays, it's more courageous -- and ultimately, I think, more helpful to the world -- to write a book disagreeing with Shirky ("Google and the Myth of Universal Knowledge," say, or "The Cult of the Amateur") than it is to write Here Comes Everybody.