This article entitled: In Iran, Cyber-activism Without the Middle Man, http://www.pcworld.com/article/166890, Twitter and Youtube are social networking streams used by the Iranian citizens to voice opinions that would be restricted by the Iranian government in the traditional media.
YouTube allows citizens to show video footage of what is really occurring in the streets. These things would be censored from public television. By using the web, we are not limited in what we can see in the world. Things are not hidden from us. The web tells it how it is and doesn't beat around the bush. And in this way, the citizens (in this case Iranian citizens) are telling the new stories, the new stories more coherent with their reality. Government places restrictions on what they want their citizens to be viewing and what they don't want their citizens to know. Thoreau as well as a pure democratic system of government believe that government ought to be run by the people.
Hearing, Tweeting, and Viewing the stories of citizens, of those being attacked or denied certain rights creates an appeal to unite and defy government civily.