Media analyst Clay Shirky has some interesting thoughts on the steady stream of photos, Twitter posts and videos coming out of post-election Iran:

I’m always a little reticent to draw lessons from things still unfolding, but it seems pretty clear that … this is it. The big one. This is the first revolution that has been catapulted onto a global stage and transformed by social media

I’ve been thinking a lot about the Chicago demonstrations of 1968 where they chanted “the whole world is watching.”

Really, that wasn’t true then. But this time it’s true … and people throughout the world are not only listening but responding. They’re engaging with individual participants, they’re passing on their messages to their friends, and they’re even providing detailed instructions to enable web proxies allowing Internet access that the authorities can’t immediately censor. That kind of participation is reallly extraordinary.

Shirky goes on to suggest that microblogging service Twitter has made the most impact on the events in Iran and their coverage:

One thing that Evan (Williams) and Biz (Stone) did absolutely right is that they made Twitter so simple and so open that it’s easier to integrate and harder to control than any other tool. At the time, I’m sure it wasn’t conceived as anything other than a smart engineering choice. But it’s had global consequences.

Twitter is shareable and open and participatory in a way that Facebook’s model prevents. So far, despite a massive effort, the authorities have found no way to shut it down, and now there are literally thousands of people aorund the world who’ve made it their business to help keep it open.

While Twitter has been huge in the last few days, YouTube videos, like the one embedded above, and the images coming through sites like Flickr are incredibly important, too, because they let you see the scale of what’s happening.

Iran’s military is warning online media of a crackdown over coverage of the country’s election crisis. The country is trying to block access to social media sites, and said that Iranian Web sites and bloggers must remove any materials that “create tension” or face legal action.

At this point, though, it looks like the only way to cut off the flow of citizen media in and out of Iran is to eliminate access to the Internet itself.

See Shirky’s full comments at the TED site.