Background Briefing - 15 May 2011 - Digital revolutionaries under surveillance

In Egypt democracy activists called themselves the Facebook revolutionaries, but in China there are fears the social networking sites will be used to spy on dissidents. For governments, social media represent easy access to their citizens, for good or ill. But for digital entrepreneurs, including the odd Russian billionaire, there must be money in it, if they could only find a way. No-one knows where it will go next. Reporter: Stan Correy