As violence flared Sunday between anti-government protesters and Iranian security forces, the world witnessed a second surge in Iranian “citizen journalism” via Internet platforms such as YouTube, Twitter and Facebook. It has been years since a Western news organization has been able to operate a news bureau out of Tehran. Reporters Without Borders and The Associated Press have reported that a number of journalists and editors have been arrested in Iran since Sunday. Reporters Without Borders also reported that computers were confiscated from the offices of a weekly newspaper and that yesterday “most independent or opposition Web sites were rendered inaccessible within Iran.” The Associated Press has reported that cell phone and text messaging services within Iran have been restricted. It’s clear the Iranian government is attempting to keep professional journalists from documenting the turmoil in the country’s streets. It’s also apparent that the more the Iranian government tries to suppress the mainstream press, the more active the Iranian citizenry becomes in filling journalists’ shoes, broadcasting to the world scenes of Iranian unrest. Dozens of videos, many shot with cell phones or digital cameras, have been posted to YouTube (and aggregated by Frontline’s Tehran Bureau). Twitter users apparently based in Iran, like “Mani” and “Sootak“, are tweeting photos of the chaos. Because it is so difficult for mainstream journalists to report out of Iran, news agencies such as the BBC, ABC and The New York Times have made use of such videos and photos in their reporting, and CNN has been actively soliciting citizen reports from Iran via Twitter. Since photos and videos are frequently reposted by activists, it is often difficult to identify the original producer of the material. Twitter has also become a platform for defiant statements of anger and frustration against the Iranian government. “Iranian government is now under total control of IRGC and thugs,” Twitter user “Mehrdad” wrote yesterday of the Iranian Revolutionary Guard Corps. In response to a segment aired by state-controlled Islamic Republic of Iran Broadcasting, Twitter user “MoInIran” wrote, “I wished I could get a metal stick and beat this IRIB guy to death.” Posting such images and messages online is no anonymous act of false bravado. Many activists blur faces in photographs before posting them online, in an effort to protect those pictured from being punished by Iranian officials. They also withhold their real names when they post to Twitter and YouTube. Even if protesters conceal their identities online, however, it’s possible for the Revolutionary Guard to identify and find (and punish) Iranian activists via their IP addresses.