TEHRAN -- Iranians lost unrestricted access to Facebook and Twitter on Tuesday almost before they knew they had it, leaving many people wondering whether the opening was deliberate or the result of some technical glitch.
The Web sites had been blocked since huge anti-government protests exploded following the disputed presidential election in 2009. But for almost a full day on Monday, jubilant Iranians were able to call them up without resorting to VPN software, which is illegal.
The Internet has long been a battleground in Iran between those pushing for more personal freedoms and hardliners who feel they must protect society from dangerous influences -- a struggle that may have played out on Monday.
Iran's new president, Hassan Rouhani, has repeatedly promised an easing of Internet restrictions. He has a Twitter account which is managed by people close to him. His foreign minister, Mohammad Javad Zarif, has Facebook and Twitter accounts where he actively engages in debates.
Political insiders say Monday's mysterious unblocking of Facebook and Twitter was an attempt by certain groups within the Iranian political establishment -- it was not clear exactly who -- to measure the reactions of Internet users.
"Monday's move was a test conducted to see what people would do if Facebook and Twitter were opened," said one source close to the new government who asked to remain anonymous because of the secrecy surrounding the matter. "Apparently the test results have been unfavorable, because the sites have been closed again."
That was echoed by Farshad Ghorbanpour, a political analyst close to the government. "It seems to me the authorities wanted to see what would happen if the Web sites were opened," he said. "This is not uncommon in Iran."
It is unclear exactly what the authorities would have been seeking to find out with such a test.
Conservatives tended to favor a technical glitch as the explanation for the unblocking of the Web sites. "God willing this has been a mistake," Judge Abdolsamad Khoramabadi, a prominent hardliner, told the semi-official Mehr news agency. "But if this was done on purpose we will confront those behind it."
Mr. Khoramabadi warned on Sunday that Facebook is destroying families, saying that it is the cause of one-fifth of all divorces in the United States. "Some officials seem to be unaware of the dangers of this Web site when they speak of unblocking it," he told the Khabaronline news agency.
On Tuesday, the semi-official Fars news agency published a long article pointing out the dangers of social media, saying that Facebook is blurring the lines between private and public.
"Many women choose profile pictures without their Islamic scarves. Facebook is aiming to blur our cultural lines between private and public," Fars wrote in an editorial. "There are no borders on Facebook, this is extremely dangerous."
But in another sign that Monday's unblocking was a test, a famous TV anchor, Reza Rashidpour, who campaigned for Mr. Rouhani, congratulated Iranians on Monday for gaining unrestricted social media access but also cautioned them. "We hope our people will restrain themselves and our officials will be patient."
If indeed a test was conducted, it seemed to reveal a pent up hunger for less restriction and more interaction. One tweet by this reporter -- 'Hello world, we are tweeting without restrictions from Iran." -- was retweeted nearly 900 times, with many Twitter users welcoming Iran to Twitter and Iranians saying they could not believe what was happening.
But the window quickly closed. Rayaneh, a poet, said she tried to get online on Monday to post a message to the world. "1, 2, 3… 1,2,3… Can you hear us? We are testing if Facebook is running without VPN here," she said. "But by that time the filters were back on," she said.
This article originally appeared in The New York Times.