Reuters reports today that the BBC is the victim of a "sophisticated cyber-attack following a campaign by Iranian authorities against its Persian service, director-general Mark Thompson said on Wednesday."
Thompson, says Reuters, said there have also been "attempts to jam satellite feeds of the British Broadcasting Corporation services into Iran and to swamp its London phone lines with automated calls."

It is illegal to own a satellite receiver in Iran, but plenty of people do, and the BBC is an extremely popular channel to tune into. In late February, the BBC reported that their audience in Iran had doubled to six million "between 2009 and 2011." The BBC broadcasts in many languages all over the world.