Iranians by the thousands Tweeted, Facebooked, blogged, video streamed and posted on scores of Web sites to share the events with the rest of the world, thwarting government attempts to censor coverage of the post-election violence.
Twitter in particular appeared so powerful that the U.S. State Department even asked the micro-blogging service to delay a scheduled network upgrade to ensure Tweeting Iranians wouldn't lose access.
But while Twitter and its new media cousins have given millions of people around the world the unprecedented ability to speak out and quickly organize against repressive governments, some experts caution that social media doesn't only benefit the social activists.
Authoritarian regimes in Iran, China, Egypt and elsewhere have already become equally -- if not more -- social media-savvy, and the consequences of that reality could significantly hinder efforts to democratize digitally, experts say.
"I'm not sure we understand the implications of building public spheres," said Evgeny Morozov, Yahoo! Fellow at Georgetown University's E.A. Walsh School of Foreign Service.
In a U.S. Helsinki Commission hearing on new media in authoritarian regimes, Morozov last week warned that new media "will power all political forces, not just the forces we like."
Despite efforts to encourage the growth of pro-democratic groups online, he said research into the blogospheres in Egypt, Palestine and Russia suggest that the Muslim Brotherhood, Hamas and groups of Russian nationalists and fascists are among the most active users of blogs and social media.
"Blind support for promoting blogging and social networking may have a lot of very unpleasant unexpected consequences," Morozov said.
While it's true that governments may have lost some power to Internet-based modes of communication that empower many voices, he said authoritarian regimes have benefited from those same communication channels in other ways.
"The Internet has made it much more effective and cheaper to spread propaganda," Morozov told ABCNews.com.
In Russia, the government befriends new media entrepreneurs who spin online conversation in the government's favor. The Chinese, Morozov said, have created a "50 cent party" composed of thousands of people across the country who get paid 50 cents for each comment they leave online.
For some authoritarian governments, new media can be used to give the appearance of openness and legitimacy.
In a piece written earlier this year for the human rights blog openDemocracy.org, Babak Rahimi, a professor of Iranian and Islamic Studies at the University of California, San Diego, wrote about the "politics of Facebook" in Iran.
Despite blocking a number of dissident Web sites ahead of the presidential election, in February Iranian authorities unblocked the popular social networking site Facebook. Why would the state unblock Facebook while limiting access to other Web sites?
Part of the reason could be to encourage younger people to vote, thereby boosting electoral participation and signaling state legitimacy, Rahimi wrote.
Another reason could be to identify dissenters.