When Houshang Fanaian joined Facebook last year, little did he expect it would land him in an Iranian prison.
That's exactly where he finds himself today, however. In late May, the 47-year-old Baha'i had one year tacked on to a larger prison sentence due to his activities on the social-networking site.
Iran has blocked access to Facebook, but that has not prevented tens of thousands
of Iranians from joining the site to connect with each other and share ideas, pictures, and even sensitive political content.
For the most part, the Iranian regime stood idly by if its efforts to block Facebook were circumvented.
Fanaian's sentencing is a rarity, but his case and others indicate that Iranian authorities are keeping a closer eye on Iranians' Facebook activities.
Among the more recent posts on his Facebook page are pictures of cute babies, an article about the "negative side effects" of artificial sugar, and a few news stories about the arrests of Baha'is.
The Baha'i faith is not recognized by the Islamic republic, and Fanaian's wife believes that his activism on Baha'i issues led to his February arrest and subsequent charges of acting against national security and insulting the country's supreme leader.
Warnings, Harassment, And Surveillance Efforts
Janet Khanlari tells RFE/RL's Radio Farda that the initial charges stem from her husband's faith and, specifically, a letter he wrote to Supreme Leader Ayatollah Ali Khamenei in which he voiced criticisms about the problems Baha'is face in Iran.
Jailed Baha'i activist Houshang Fanaian
In May he was sentenced to four and a half years in prison on the charges. One year of his sentence was for disseminating anti-state propaganda on Facebook.
Khanlari maintains that the Facebook sentence is just "an excuse" to pressure him.
"[The authorities] say he encouraged young people to become Baha'i through his Facebook page, but all his Facebook contacts are relatives who were [already] Baha'i," she says.
The case highlights the Iranian regime's attempts to gain control of citizens' online activities, which have continued despite warnings, harassment, and surveillance efforts.
Many Iranian opposition activists and human rights defenders use online tools like Facebook to spread news about the beleaguered opposition movement, to report oppressive activities by the state, and to discuss other sensitive subjects.
Facebook, despite efforts to block it, has proven particularly popular in Iran. While many users opt to log on using pseudonyms, the site is viewed as a space where activists can discuss political developments relatively freely and with people both inside and outside the country.
In February, an opposition protest called by Green Movement leaders Mir Hossein Musavi and Mehdi Karrubi to support the Arab uprising attracted tens of thousands of Iranians to the streets.
Those protests were advertised widely on Facebook, which may or not have caught the eye of the Iranian regime. What is known is that the authorities have subsequently employed threats or worse -- Musavi and Karrubi have been under house arrest since their calls for protest -- to prevent more such rallies from being held.
Mahmood Enayat, director of the Iran Media Program at the University of Pennsylvania, says Iranian officials are concerned about any type of public gathering, be it offline or online.
Iranian media scholar Mahmood Enayat
"They don't even let people gather in the streets for a funeral," he says. "Facebook allows gatherings to take place in cyberspace between people who share the same ideas. [Iranian officials] don't want these intergroup relations to take shape."
Reports and interviews with activists suggest authorities monitor the online activities of rights campaigners and intellectuals they suspect of engaging in what Iran sees as antistate activities.
Several student activists -- suggesting the involvement of Iranian intelligence bodies -- recall examples in which individuals with spurious identities have tried to "friend" them on Facebook.
One activist who was detained in the government crackdown on dissent that followed the contentious 2009 presidential election says he was asked during interrogations whether he had a Facebook page. He says had one, but decided not to reveal it, and the interrogator never verified his claim.
Another former detainee says several individuals who were held in Tehran's Evin prison with her said they had come under pressure over their Facebook activism.
A female journalist and opposition supporter who spent several months in prison in 2009 says she has been warned about her online activities.
She says she tries to be careful while posting articles and updating her Facebook status, except in cases when she feels she has to stop practicing self-censorship. "When some of the political prisoners, including those I know personally, are facing a critical situation, I tell myself: 'I have to raise my voice. Let [the officials] do whatever they want,'" she says.
A Safer Place Than The Street
Sajjad Veis Moradi, editor of the Daneshjoonews website, which covers Iran's student movement, says he has documented cases of students who have come under pressure at universities over their Facebook pages.
"Disciplinary committees have summoned students based on the information they had received from the university's security forces or the Basij militia," Moradi says. "We had cases, for example, of students who had posted pictures of private parties on Facebook. They were summoned over what was described as their immoral behavior."
Despite such reports, Enayat of the University of Pennsylvania believes Iran cannot effectively monitor the Facebook activities of its citizens. "That's why [the authorities] try to create an atmosphere of fear," he says. "To stop people from engaging in political activism on Facebook."
Fear is the reason why some Iranians have decided to have two Facebook pages: one under their real name in which they stay away from topics that might get them into trouble, and another under a fake name in which they actively oppose and criticize state policies and other sensitive issues.
One Facebook user says the two-page solution gives him a place to vent his anger at Iranian leaders over the poor state of the economy and lack of freedom, without having to pay the high price of protesting in the street.
Radio Farda broadcaster Farin Assemi contributed to this story