Iran clamped down on Tuesday on independent media in an attempt to control images of election protests, but pictures and videos leaked out anyway -- showing how difficult it is to shut off the flow of information in the Internet age.
The restrictions imposed by the government made such social-networking sites as Twitter and Flickr more prominent -- with even the US State Department calling on Twitter to put off a scheduled shutdown for maintenance.
Iranians were posting items online, but it wasn't known how much of that information was being seen by others inside the country. And although some of the posts on Twitter appeared to be from users in Tehran, others clearly were not.
Following a massive opposition rally on Monday, authorities restricted journalists -- including Iranians working for foreign media -- from reporting on the streets. They could effectively only work from their offices, conducting telephone interviews and monitoring official sources such as state TV.
Some foreign journalists were forced to leave Iran because the government wouldn't extend the visas they received to cover Friday's election, in which President Mahmoud Ahmadinejad was declared the landslide winner.
"Clearly, when our journalists can't go out and see things and talk to people, our ability to tell the story is not as good as when we are able to go out to report and take pictures and video," AP Executive Editor Kathleen Carroll said.
When controls are imposed, "we work with those restrictions, keeping in mind our ultimate goal is to be able to do our jobs as journalists," she said.
The London-based Reuters news agency included an editor's note on its stories out of Iran saying its coverage was subject to a ban on "foreign media leaving the office to report, film, or take pictures in Tehran."
CNN turned in part to the social-networking sites, broadcasting images posted on Facebook and Twitter, and explaining on-air that it was using "creativity" to cover a big event under government restrictions.
"We cannot verify readily some of this material that we're going to show you," correspondent David Mattingly warned viewers. Much of the material on Twitter is posted anonymously.
CNN spokeswoman Bridget Leininger said that adding context and explaining issues was necessary when reporting with such online sources.
"We are committed to making the most information available in a tough news environment, while being totally transparent with the audience," she said.
Iranian journalists have also been targeted, including at least 10 who have been arrested, according to the press freedom group Reporters Without Borders.
