In Iran, the day of the election, the internet was shut down completely. In the last two weeks, it has been slowed down, hacked, and carefully watched. How did the Iranians set up such a deliberate firewall so quickly? Here to tell us how is Rafal Rohozinski, he is the Principal Investigator with OpenNet Initiative, a university collaboration that aims to analyze internet filtering and surveillance practices. They have a new report out, looking at the Iranian firewall. He is also CEO of Siphon, a company that sells products to circumvent firewalls.