By Maggie Shiels
Technology reporter, BBC News, Silicon Valley
Social networking tools have been used to organise rallies and protests
Twitter has distanced itself from State Department revelations that it asked the company to delay maintenance so Iranians could continue to communicate.
Twitter is one of the social networking tools being used by people inside the country to coordinate protests disputing the election result.
The planned upgrade would have cut the service at a crucial time of the day.
"The State Dept does not have access to our decision making process," wrote Twitter co-founder Biz Stone in a blog.
"When we worked with our network provider to reschedule this planned maintenance, we did so because events in Iran were tied directly to the growing significance of Twitter as an important communication and information network.
"We decided together to move the date. It made sense for Twitter and for NTT America to keep services active during this highly visible global event."
The State Department declined to give details of its contact with Twitter except to say "we highlighted to them that this was an important form of communication."
Mr Stone turned down requests by the BBC to be interviewed on the matter.
Twitter moved its maintenance work to the middle of the morning Iran time
In an e-mail he said "we've addressed this on our company blog to the extent we're willing to comment at this time."
Industry watchers however believe that Twitter would have rescheduled its planned maintenance regardless of the State Department's intervention.
"My guess is that the people at Twitter were already planning to switch things around so that people in Iran could use the service," said Professor Jonathan L. Zittrain co-founder of the Berkman Centre for Internet & Society at Harvard.
"They would have been well aware of how important their role is in all of this so I wouldn't read too much into the report about State Department involvement."
While social networking tools are proving to be crucial at this time, the unanswered question is just how groundbreaking a moment it will prove to be for the likes of Twitter, YouTube, Flickr and Facebook.
YouTube spokesman Scott Rubin is in no doubt about the answer.
"I'm likening this to the Velvet Revolution in the Czech Republic where all these barriers are placed in front of people and they keep marching. Only this time it's happening online and it's happening on YouTube."
YouTube has played a major role with videos being uploaded from inside and outside Iran and reposted around the world.
YouTube said traffic from Iran is 10% of normal
"We have been comparing our content with the official coverage coming from journalists inside the country working under severe restrictions and are seeing YouTube acting as a critical platform for citizen journalists," Mr Rubin told the BBC.
"By using YouTube, Iranian citizens are having their voices heard, their faces seen and their story gets told around the world without filtering. The real story of this election is being told by the citizen."
Mr Rubin said that, while it has had no official confirmation, it does appear that YouTube is being blocked by the Iranian government. Traffic is down by 90%.
Regardless of blocks on YouTube and other social networking sites, people are managing to work around the problem by using proxy servers to bypass censorship.
CitizenTube has posted videos on how to configure these proxy networks. It was set up by YouTube to chronicle the way people are using video to change the way they communicate.
Facebook has been blocked because of its popularity with reform supporters
One 25 year old who has found himself on the virtual front lines of this world event is Austin Heap, an IT director in San Francisco.
Over the weekend he started collating a working list of proxy server addresses and his easy-to-follow instructions on how to set one up made him famous overnight.
People contacted Mr Heap from all over the globe and sent new proxy addresses. Traffic to his site grew from a few dozen users a day to more than 100,000 in 24 hours.
Mr Heap told the San Francisco Chronicle "Most of the reactions from Iran have almost made me cry. Having somebody tell me that their family thanks me - that's the power of the internet.
"I haven't been in the middle of an outpouring like this, ever. And it makes me incredibly proud of the IT community," said Mr Heap.
While Professor Zittrain acknowledged that social networking has taken centre stage in this story he said he reserved judgement about just how seminal a moment it is for the sector.
"It just too early to say but my expertise tells me what is going on is extremely interesting.
"It seems to me to indicate the power of something I call civic technology and these aren't just technologies for civic purposes. I mean technologies that rise or fall depending on the number of people using them and how passionate they are about the technology they are using.
"It may take a while for history to sort out what has been happening this week," Professor Zittrain told the BBC.