Authoritarian regimes, alas, know how to exploit social media, too.

"The revolution will not be tweeted," Malcolm Gladwell declared in a New Yorker piece several months ago, debunking inflated faith in the power of social networking to spread democracy. "We seem to have forgotten what social activism is," he went on. "… We are a long way from the lunch counters of Greensboro." To many altruistic souls clicking away on behalf of various causes—swathing their Twitter icons, for example, in green to show solidarity with Iranian activists—Gladwell's argument was an outrage. Less excitable bloggers were put off, too: Surely social networking would only help, not hurt, the battle against authoritarianism. "Is the web doing much to help the worst African dictators or the totalitarians in North Korea?" Tyler Cowen asked on Marginal Revolution. Though "[n]ot so many data are in," he was dubious that the tweeting was helping those entrenched in power.

In a new book, The Net Delusion: The Dark Side of Internet Freedom, Evgeny Morozov scrutinizes plenty of evidence and concludes that the Web can, and does, indeed help dictators in a variety of ways. (Morozov, who was born in Belarus and researches the effects of the Internet on political behavior, also blogs for the Slate Group's Foreign Policy and has written on this subject for Slate.) We like to think that information sets us free, and that access to the Internet can lead those oppressed by authoritarians into the light of democracy. But the Internet is not a one-way street, and dictatorial regimes are quite technologically savvy. Countries like Egypt may block the Internet at times, but they can take advantage of it, too, using it not just to help track down dissidents but also to dispense propaganda. Morozov goes beyond Gladwell. It's not just that the revolution will not be tweeted. The Internet, he argues, may prevent the revolution from getting off the ground.

Take the case of the Iranian protests in 2009. "Iran's Twitter Revolution revealed the intense Western longing for a world where information technology is the liberator rather than the oppressor," writes Morozov. The "revolution" did change things for the opposition, he argues—but in the wrong direction. The Iranian government and its hard-line supporters used mobile and Internet technology all too astutely against the protesters. Gleaning information from Facebook, they sent "threatening messages" to Iranians living abroad, text-messaged Iranians to stay home and avoid the protests, and urged "pious Iranians" to fight back online.

Meanwhile, Morozov casts credible doubt on the alleged success of the protesters in mobilizing Twitter and other social media for their mission. Twitter was not terribly popular in Iran prior to the elections, with just 19,235 Twitter accounts registered in Iran, or 0.027 percent of the Iranian population. When Al-Jazeera fact-checkers tried to verify that tweets originated in Iran, they could "confirm only sixty active Twitter accounts in Tehran, a number that fell to six once the Iranian authorities cracked down on online communications." Many of the tweets that publicized the election unrest were actually coming from Iranians living abroad; Twitter may have helped spread the word internationally, but given the relatively tiny number of Iranians on Twitter, it couldn't have been used for large-scale organizing.

The most frightening evidence of the government's technological prowess was its use of Facebook to contact Iranians abroad. Such social-networking analysis holds great potential for authoritarian regimes: Activists who blithely "friend" one another make investigations much easier for authorities trying to monitor troublemakers. This "social-network surveillance" could ruin on-the-ground organizations, as members' connections to one another are revealed. In The Net Delusion, Morozov tells the story of a young activist from his native Belarus who was called into his university to talk to the KGB. (It still exists, and is active, in Belarus.) The officers had detailed knowledge of Pavel Lyashkovich's travel, involvement with anti-governmental organizations, and connections in the dissident community, merely from checking his social-networking activity. It's easy to say that Lyashkovich should have taken more care to cover his tracks. But if the point of social networking is to broadcast change, it is maddeningly circular to say that activists must hide their connections to one another.

This is just low-level social-networking surveillance. There are other unnerving technologies in the works that would make it even easier for authoritarian governments to spy on their populations. Recently, activists alleged that the Tunisian government has been siphoning login information sent to Facebook and Gmail, which enabled hackings of activists' accounts. There is also software in development at UCLA, funded in part by the Chinese government, "that can automatically annotate and comment on what it sees … obviating the need to watch hours of video footage in search of one particular frame."