Forces loyal to the hardline government in Iran have organized a cyber-attack on the Facebook pages of prominent opposition figures, according to Mousavi’s website mowjcamp.
Hackers attacked the Facebook pages of Mir Hossein Mousavi, Zahra Rahnavard, Mohsen Mirdamadi, Behzad Nabavi, and Abdellah Ramazn Zadeh on Thursday morning, local time in Iran.
These are the websites that were attacked and are no longer accessible at the moment:
niacINsight - The Blog of the National Iranian American Council (NIAC) 
Twitter is currently down as well. Coincidence?
Twitter is also down, unedpectedly. Is twitter part of the cyber attack? Any rumors?
Looks like twitter is also under attack: “Denial-of-Service Attack Knocks Twitter Offline (Updated)” http://www.wired.com/epicenter/2009/08/twitter-apparently-down/
From http://status.twitter.com/
Ongoing denial-of-service attack 2 hours ago
We are defending against a denial-of-service attack, and will update status again shortly.
Update: the site is back up, but we are continuing to defend against and recover from this attack.
Update (9:46a): As we recover, users will experience some longer load times and slowness. This includes timeouts to API clients. We’re working to get back to 100% as quickly as we can.
Mohsen sazegara’s FB has disapeared altogether. It had a support count of around 8490.
You know, with cyber attacks becoming more and more relevant in our society, maybe the government’s cyber warfare idea isn’t such a bad one. Check out this video that talks a little more in depth about what is going on with this cyber stuff.
http://www.newsy.com/videos/cyber_warfare_a_digital_dilemma