As international media outlets are being pushed off the streets of Tehran, the burden of reporting on Iran's post-election crisis is falling increasingly on online channels ranging from blogs and video sites to Twitter and Facebook.
The Iranian government raised the stakes in the Internet battle on Wednesday by spreading the word that online users could face prosecution and even execution for "incitement."
The online showdown paralleled the political showdown playing out offline: The opposition candidate in the country's disputed presidential election, Mir Hossein Mousavi, called for a fresh round of mass rallies on Thursday, despite the government's crackdown. President Mahmoud Ahmadinejad's government accused Western countries of "intolerable" interference in Iran's internal politics. And Iran's supreme cleric, Ayatollah Ali Khamenei, was expected to lay out his plan for easing the crisis during Friday prayers.
The potential options include a partial or full recount of the votes from the election, which had Ahmadinejad winning in a landslide. That outcome sparked waves of protests from Mousavi and his supporters, who had claimed victory and accused the government of vote fraud.
Amid the political maneuvering, a high-tech, international cat-and-mouse game was playing out online:
- Iranian activists passed along reports about rallies and casualties anonymously via proxy Web servers set up abroad. "It's absolutely crucial for people to be able to use these Web sites, because otherwise a lot of the news may not have gotten out," an Iranian student who gave his name only as Sanaz told NBC News.
- The Iranian government reportedly targeted the protective Internet addresses, or IP addresses, for network attacks. "Do not publish proxy IPs!" Twitter users warned each other in a flurry of messages. Iran's mobile phone and Internet networks showed signs of a slowdown, which may be part of a strategy to reduce the information flow.
- The opposition's supporters hit back by blocking the government's own Internet addresses from carrying out attacks.
The Twitter social-networking service — which lets users around the world post 140-character updates via the Web, mobile phones or specialized computer applications — is taking center stage in the election's aftermath. But Abbas Milani, director of Stanford University's Iranian studies program, noted that Iranians had been using social networking tools, blogs, cell phones and text messaging long before the current crisis.
"What we have here is a network that has been long established for various uses," Milani said. "People have been using this for [organizing] everything from poetry readings to underground rock music. That's just one step away from using it for political purposes. Now it's becoming a reality."
Milani said that Iran ranks high on the list in bloggers per capita, perhaps at the top. "It is a Weblogging nation, with an estimated 18 million people who use the Internet," he said.
Iranians have also embraced mobile phones in recent years, said M. Rahim Shayegan, an expert on Iranian language and culture at the University of California at Los Angeles. "Since 60 percent of the Iranian population is age 30 and younger, they're not only in possession of a cell phone, but are also aware of how these [various] technologies work," he said.
"Everyone is a reporter," Shayegan said.
An Iranian blogger told msnbc.com in an e-mail that Twitter, YouTube, Facebook and other Web sites are filtered by the government, "but we use anti-filters and proxies to access this Web world." (The blogger's name and Web address are being withheld to protect his identity.)
If the Iranian opposition's supporters are unusually savvy about online communication, so are Iranian government agencies. Over the past couple of days, there have been increasing reports about government agents masquerading online as opposition activists or foreign journalists. That has sparked the rise of Web sites that list the Twitter usernames and Web addresses of suspected spies.
Some Iranians have reported receiving automated phone calls, apparently placed randomly, warning them that the authorities knew what they were up to and would take action. Because of all the anonymity, and because of the official clampdown on reporting, many of the reports being distributed online — for example, about violent clashes or high-profile arrests — were difficult to verify.
Authorities forbade foreign journalists from filming opposition-led protests and pressed them to leave when their visas expired. At the same time, they allowed somewhat more open coverage of the demonstrations by Iranian media. Photographs released by the pro-government Fars News Agency showed the streets of Tehran filled with Mousavi's supporters. (However, another photograph, purportedly printed in a pro-government newspaper, appeared to have been altered to inflate the size of a pro-Ahmadinejad demonstration.)
The key question is, where is all this going? There are already signs that the government's clampdown is having an effect on the so-called "Twitter Revolution," and a group of activists at the University of Chicago have already set up a fax-to-Web service in case Iran's online links to the outside world are cut off completely.
"The government is trying to do everything it can to curtail the free dissemination of information, and in fact, this is one of the most important issues that large percentages of the people, including people within the established revolutionary government, do not want to happen," said Hossein Ziai, director of Iranian studies at UCLA.
Stanford's Milani said he doubted that government officials could put a complete Internet cutoff into effect. "They might succeed in suppressing the movement, but they won't succeed in dismantling this. They need the Internet as much for their own work as the people do for theirs," he said.
But high-tech communication links provide no guarantee that free expression will remain free — or that the world will remain interested in the outcome.
"The bottom line is that these things are transitory," said Hanson Hosein, a former Middle East correspondent for NBC News who now heads the University of Washington's digital media program and is monitoring Iran's post-election crisis. "They're used for the moment, and they create strong passion, but the passion tends to dissipate once the goal is reached or not reached. ... That's the nature of social media."
In fact, there's a danger in giving too much emphasis to the role played by online media in Iran's political crisis, said Gaurav Mishra, co-founder of 20:20 Web Tech, a social media research and analytics company.
"Calling what's happening in Iran a 'Twitter Revolution' is not only distracting but also dangerous," he wrote on his blog, "because it reduces a legitimate broad-based grassroots movement to what's quickly becoming a cliche."
is msnbc.com's science editor. Suzanne Choney writes about wireless technology and other tech topics for msnbc.com.