About 30 million Iranians found that they could no longer access their email and Facebook accounts after the Iranian government blocked several sites Thursday, breaching its official communications protocol.
Speculation is rife that the sites were blocked due to the upcoming anniversary celebration in honor of the 1979 Islamic Revolution in Iran, as the authorities fear an uprising sponsored by the opposition during the month-long celebration.
The anti-regime protests in 2009 against the disputed re-election of President Mahmoud Ahmadinejad were greatly coordinated over social networking sites.
Internet users in Iran had been employing Tor software and networks to circumvent government censorship. However, recent reports suggest that even these tools - which hide one's IP address - have been deemed ineffective in accessing Facebook and emails.
Internet users and bloggers in Iran termed the Internet censorship as show of force by the government.
Iran had recently announced its plans to establish its own national network to replace the World Wide Web.
The militant Islamic regime of Iran has a bad track record with regard to Internet freedom. In April 2003, Iran imprisoned a blogger, Sina Motallebi of the popular weblog RoozNegar.com, as part of a crackdown on immorality, dissent and secularity.
In October last year, an Iranian official - who dubbed Facebook users a threat to Islamic values - expressed concern that expansion of social media networks was harming the nation and society.
Internet censorship has been in place for quite a long time in Iran, as the authorities fear an anti-government revolution like the Arab Spring, which rocked countries including Egypt, Tunisia, Libya, Syria, Yemen, Iraq, Bahrain and Jordan.