In the Canary restaurant on Westwood Boulevard in Los Angeles, where nearly every shop and café is Iranian-owned, pictures of the demonstrations run constantly on a battered television tuned to one of more than 20 Persian TV stations in the city. In a corner, photographs of the Shah are a reminder of a call to arms from an earlier generation, who fled Iran after the Islamic Revolution.

Ehsan Zahedani, 27, is sitting at a table, checking his Facebook page. The student of politics and Iranian studies at nearby UCLA has more than 1,950 “friends” and his profile page is filled with posts, pictures and links to videos on YouTube — all about the protests in Iran.

Mr Zahedani is part of an informal online network across Southern California working to support the protesters on the streets and broadcast their message to the world.

He has helped to co-ordinate a series of demonstrations to express peaceful solidarity and call for fresh elections, using Facebook and a well-worn Samsung smartphone. He wears a green scarf — the colour of the demonstrators. “Green is our symbol against fraud, against cheating, for freedom and democracy. We want our stolen votes back,” he said.

Los Angeles is the centre of the Iranian diaspora in the US. There are more than one million Iranians and Iranian-Americans in California, the vast majority in and around Los Angeles. Many came over in the aftermath of the revolution 30 years ago but others — students and professionals — are recent, internet-savvy arrivals.

Roja Bandari, 29, is a doctoral student of electronic engineering at UCLA. She is part of the Where is my Vote movement that has flooded Facebook and Twitter with its green logo. It was set up before the Iranian election to encourage people to vote, but once the result was in, its members put together a series of popular demonstrations across the US.

The movement has gained a Facebook page with thousands of members and a website, whereismyvote.org. “What we want to do is to help our people in Iran get their voices heard overseas. We want to amplify their voices to the world,” Ms Bandari said.

A guerrilla war of slogans and strategies has played out on Twitter and websites such as YouTube as protesters have sought to get round the Iranian Government’s efforts to shut down communications outlets. Iranians in California are determined to do their bit to make sure that the censors do not win. Web-savvy supporters have pitched in to give technical support to those in the homeland trying to get round the blocks.

They have set up proxy servers, which can help to bypass censorship by hiding the identity and location of users. Hundreds of proxy servers all around the world have been set up for use inside Iran and, as they have been shut down, others have popped up.

One blogger put up an “Iran Election Cyberwarfare Guide” detailing how activists could support Iranian tweeters. Advice included: “Help cover the bloggers: change your twitter settings so that your location is Tehran and your time zone is GMT +3.30. Security forces are hunting for bloggers using location and timezone searches. If we all become Iranians, it becomes much harder to find them.”

Protesters are also using Twitter to organise “denial-of-service” attacks against Iran Government websites — co-ordinated attempts to shut down their servers by overwhelming them with traffic.

Ms Bandari says she knows that people in Iran are aware of the massive support movement online: “They have told us thank you, you are giving us energy with your support.”

Alireza Shebani, 28, is another member of the Where is my Vote network. Like others of this younger generation, he has no interest in refighting the battles of the past.

While many older Iranian expats want to oust the Islamic regime and fondly remember the days of the Shah, they take a more pragmatic view. They travel back and forth to Iran regularly. Most protests on the streets of LA this week have experienced angry exchanges between the generations as students sought to focus on calling for fresh elections in Iran while flag-waving dissidents want to roll back the Islamic Revolution.

Mr Shebani, a quantum physics researcher at the University of Southern California who is just about to start a postdoctoral thesis at Princeton, says: “We are just a network: we have a simple demand — we condemn this fraudulent election and demand a new election is held with transparency.” He has managed to keep in contact with his family in Tehran by phone and e-mail, but knows that the authorities are able to filter communications: “We have heard that people have received a recorded message on their phones saying we know that you have attended a demo.”

At Radio Iran, a Farsi language station, comments pour in from across the world. The assistant manager, Poopak Mozaffari, said: “Without the internet I could not tell what was happening. Now everyone knows.”

Tweets from Tehran

There is a long list of rebel students given to all universities, & security is to arrest them on sight [12.05]

Govt is now running a mass media propaganda about US & Israel joint force working in some internet sites against Iran [12.10]

Any hope we had for parliament to stand against Ahmadi is now ruined: they openly support government today [12.15]

Expect clashes at Friday’s prayer in Tehran. Khamanei supporters to come from all corners of Iran [17.20]

State TV & Radio went berserk today, all they saying are Mousavi’s supporters are all criminals & they will stop us at any cost [12.15]

State TV has been showing a lot of new movies lately, seems like an attempt to get people to stay home [17.40]

We have to leave, it’s not safe here anymore! wish us luck! [12.15]

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