At Hacker News, a user named "Sara70" posts:
I'm writing this to report the serious troubles we have regarding accessing Internet in Iran at the moment. Since Thursday Iranian government has shutted down the https protocol which has caused almost all google services (gmail, and google.com itself) to become inaccessible. Almost all websites that reply on Google APIs (like wolfram alpha) won't work. Accessing to any website that replies on https (just imaging how many websites use this protocol, from Arch Wiki to bank websites). Also accessing many proxies is also impossible. There are almost no official reports on this and with many websites and my email accounts restricted I can just confirm this based on my own and friends experience. I have just found one report here. The reason for this horrible shutdown is that the Iranian regime celebrates 1979 Islamic revolution tomorrow.
Jake Appelbaum and the Tor Project folks confirm that Iran is partially blocking encrypted network traffic, and they are trying to help ensure free and safe access for activists (and everyone else inside the country).
PHOTO: Iranian schoolgirls chat online at an internet cafe which is exclusively for females, near the city of Karaj, 60km (38 miles) west of Tehran, May 24, 2007. REUTERS.