Iran: Internet Blackout Ahead of Protest Day  · Global Voices
Fred Petrossian

Slow Internet and filtering is a daily reality in Iran, but in recent days reports from inside the country say that web email and secure Internet (https:) has become inaccessible, and that the Internet is so slow that anti-filtering software fails to open web pages. The partial blackout began on Thursday, February 9, 2012.
While Iranian authorities have been silent, some bloggers speculate that the reason for the blocking is a planned protest on February 14 (in the Iranian calendar, 25 Bahman). The Tuesday protests will mark the one year anniversary of demonstrations called by Iranian opposition leaders in 2011, in solidarity with the people's uprisings in Egypt and Tunisia. The physical repression on this day was brutal and left at least two people dead in Tehran.
An Internet cafe in Tehran, Iran. Photo by Mr_L_in_Iran. Copyright © Demotix (24/02/11)
The blog Azadi-Esteqlal-Edalat (Freedom, Independence, Justice) writes [fa]:
Khamenei's regime is scared since the Green Movement has invited people to restart protests. According to some reports, in most parts of country from Tehran to Ardebil, people have no access to Gmail, Yahoo mail, Google or Google+. This blocking can be considered as the regime's attempt to stop Green activists from informing people to take part in demonstrations in the final days of February. The regime's action is useless because green activists have already informed their friends and family members, and developed creative means of passing on the message, such as writing slogans on bills of money.
Dara 1390 says  [fa]:
Without any doubt the February 14th demonstrations are the reason why the government has interrupted the internet. They are afraid of any kind of demonstration in the streets. We do not know how people will react on February 14 but the regime is making itself ready for the day.
Another blogger, Mborjan writes [fa]:
Since Thursday any access to Gmail, Facebook and https sites has become impossible, at least in Isfahan. I heard this only happened in big cities. In small cities and villages things are as usual.
Yadasht Ha (means ‘notes’) says [fa] with irony that if it becomes necessary, “We will use pigeons instead of national email.”
Bani Man also reports [fa] that as the protest day approaches, the regime blocked Gmail and Faceboook. The blogger quotes a Forbes report that as Iran cracks down online, the software Tor for anonymous online communication, is testing undetectable encrypted connections.