A panel of experts warned lawmakers on Thursday about the looming threat of a cyber attack emanating from Iran, an increasingly isolated nation that has been linked to numerous attacks against the United States in recent years including a plot last year to assassinate the Saudi Arabian ambassador to the United States in Washington, D.C.

Although some computers at Iran's Bushehr nuclear reactor were infected by the Stuxnet worm, none of the facility's crucial control systems were affected, Iranian officials claimed Sunday.

Iran's Islamic Revolutionary Guards Corps hacked into 29 Web sites affiliated with U.S. espionage networks, Iran's semi-official Fars News Agency reported on Sunday.

Iran's government in recent days has tried to cut off Internet access for most of its election protestors by shutting down routers at the nation's perimeters, ripping satellite dishes off roofs, cutting cables and turning off telephone switching networks.

Social networking site Facebook has been blocked in Iran since Saturday, according to the country's opposition, as opposition voters increasingly turn to online tools like social networking to promote their candidates.

Spammers are never far from a hot story, it seems, and in the past day they've been flooding Twitter with phoney messages about Iran and the latest iPhone 3.0 operating system.

As the Internet becomes a more important path for information between Iran and the rest of the world, Google has added support for Persian to its Google Translate service.