The social networking websites which helped mobilise anti-regime protests in 2009 are buzzing again -- this time urging Iranians to be sure to vote on Friday when Iran elects a new president.
"I will vote," wrote Rahele, a pro-reform voter, on her Facebook page. "Even if there only exists a one percent chance that my vote will be counted, and even if I will have to choose between the worse and the worst, I will vote."
Friday's election is the first since 2009 when the disputed re-election of President Mahmoud Ahmadinejad sparked massive anti-regime street protests after his opponents alleged widescale voting fraud.
The organisation of the demonstrations was aided through use of text messages and popular social networks, including Twitter and Facebook, the domain of tech-savvy pro-reform voters.
The protests and the pro-reform campaign they supported, the so-called Green Movement, were eventually crushed by the security forces, with dozens of people killed and many more imprisoned.
As part of the crackdown on the reform movement, the government blocked access for ordinary Iranian Internet users to social networking and tens of thousands of other websites. It also banned the use of software to bypass those restrictions.
The rout of the reformists and the placing under house arrest of their leaders, Mir Hossein Mousavi and Mehdi Karroubi -- who claimed Ahmadinejad had been fraudulently re-elected -- left pro-reform supporters disillusioned, with many vowing to never vote again.
But their hopes were rekindled a week ago when the sole reformist standing in this year's election, Mohammad Reza Aref, performed well in live televised debates -- the highlight of the subdued, short election campaign.
His showing resulted in a surge of support from many pro-reform Facebook members who managed to bypass the increasingly harsh regime-imposed restrictions to get online and engage in discussions, while urging everyone to vote.
Aref was this week asked by former president Mohammad Khatami to withdraw from the race in order to boost the chances of moderate Hassan Rowhani, a former nuclear negotiator, who opinion polls say has a better standing in the election against a host of conservatives close to supreme leader Ayatollah Ali Khamenei.
Aref's withdrawal and the endorsement of Rowhani by Khatami and former president Akbar Hashemi Rafsanjani -- who himself was disqualified from contesting in Friday's poll -- brought a new impetus to the campaigning on Facebook.
Many who planned to abstain from voting are having a change of heart and are now supporting Rowhani.
Drawing a parallel with his love life, one Facebook user said in Farsi: "The girl (I like) has a boyfriend. She is in love with him. And she doesn't even live in Iran. But I still 'Like' her photos. Why? Hope! I have hope -- and you are telling me not to vote?"
Some users have changed their Facebook profile picture to "I Vote", projecting it against a background of purple, the colour of Rowhani's campaign.
Some others have chosen a picture of a key, Rowhani's campaign symbol which symbolises his promise to "unlock the problems" of Iran.
"I will vote for Rowhani, even though I do not know him at all and did not want to vote until yesterday," said a man named Ali on his Facebook page. "I will vote because the consensus of those wanting to save Iran is on Rowhani."
Rowhani faces competition from four leading conservatives who have failed to coalesce behind a single candidate.
Among them are Tehran mayor Mohammad Baqer Qalibaf and top nuclear negotiator Saeed Jalili, both of whom like Rowhani are active online, including on Twitter.
Iran analyst Reza Marashi of the US-based National Iranian American Council advocacy group told AFP that Rowhani's chances would diminish "if large numbers of voters decide to stay home."
Not all pro-reform voters are confident of Rowhani's promises of more freedom, pointing to his record as secretary of Iran's Supreme National Security Council.
"I do not trust him," said one user. "All those who have enthusiastically jumped on the Rowhani bandwagon should know that his records show when it counts, he will put the interests of the regime before those of the people."
The remarks referred to Rowhani's alleged role in ordering the suppression of student protests in 1999 and 2001.
Rowhani has promised to improve Iran's image internationally, dented during eight years of Ahmadinejad's presidency, and also try to secure the lifting of harsh Western economic sanctions through negotiations with world powers suspicious that Iran's nuclear drive has military objectives.