Facebook has 20 million users worldwide, is worth billions of dollars and, if internet sources are to be believed, was started by the CIA. The social networking phenomenon started as a way of American college students to keep in touch. It is rapidly catching up with MySpace, and has left others like Bebo in its wake. But there is a dark side to the success story that’s been spreading across the blogosphere. A complex but riveting Big Brother-type conspiracy theory which links Facebook to the CIA and the US Department of Defence.