There is a place on the internet where almost two billion of us regularly go – many of us, every day. Facebook: the social network which Mark Zuckerberg started in his university dorm room and which has grown, in a little over a decade, into one of the most valuable companies in the world. But what does Facebook’s lines of computer code do with the data we give it – and what could it do in the future? Just how powerful is Facebook's algorithm? The answer will surprise you. Producers: Estelle Doyle and Sarah Shebbeare Editor: Richard Knight (Photo: Facebook CEO Mark Zuckerberg delivers a keynote address during the Facebook f8 conference in San Francisco, California. Credit: Getty Images)