Word of the opening of Iran's blocked social media sites was spread, of course, by social media itself: in celebratory tweets and breathless Facebook posts.
Hours later, the same sites today chewed over the sobering reality that the four-year-old firewalls were back in place.
Iran's Internet overseers blamed a "technical" glitch on the brief window to the Web.
But others interpreted the seesaw events as signs of growing internal struggles between the moderate-leaning President Hasan Rouhani who has promised to ease Iran's cyber-censorship and hard-liners in the Islamic establishment who see no benefit in lifting restrictions intended to foil potential political opponents and reformists.
The chances are highly unlikely that Iran's secretive Web watchers will provide a full accounting of the brief freedoms, which allowed users to access banned sites such as Twitter and Facebook directly rather than having to use proxy servers that bypass Iranian controls.
The semiofficial Mehr news agency quoted Abdolsamad Khoramabadi, a member of the board overseeing the Internet, as saying the filters were temporarily removed late yesterday by a "technical failure regarding some Internet service providers." He warned, too, that an investigation will also study the possibility of an inside job.
"We are probing it," he said.
Some Rouhani backers, however, already believe they have the answer: His government had a hand in freeing up the Internet, even if briefly.
Scores of Facebook users quickly posted "Rouhani, Mochakerim," or Farsi for "Thank you, Rouhani."
"God liberated Facebook," wrote Mohammad Reza on his Facebook account.
"This isn't really about a glitch even if one really happened," said Scott Lucas, an Iranian affairs expert at Britain's Birmingham University and editor of EAWorldView, a foreign policy website. "The bigger picture is that the Internet is central to the political battles inside the country in both the direction of domestic and foreign affairs."
The clampdown on Iran's social media was in response to the street riots and unrest after the disputed 2009 re-election of Mahmoud Ahmadinejad, whose opponents were among the first in the Middle East to harness the Web to organize protests.
Ironically, Iranian officials also have recognized the usefulness of the social media they consider too dangerous to be allowed in the public domain.
