"What's on your mind?" It's the friendly Facebook question which lets you share what you're thinking and what you've been up to. It's also the question that unlocks the details of your life and helps turn your thoughts into Facebook's profits. Four Corners explores the world of Facebook and how your data is being mined to drive the huge success of the social media giant. Reporter Peter Greste examines the Facebook business model and shows why your private life is making them billions. The program investigates how Facebook has the ability to track much of your browsing history, even when you're not logged on, and even if you aren't a member of the social network at all. And shows how the methods used to deliver targeted advertising also drives what 'news' appears in your Facebook feed, and why you are unlikely to see anything that challenges your world view. This feedback loop is fuelling the rise and power of "fake news". With more than 16 million Australian Facebook accounts, joining more than a billion other users, Four Corners investigates how much we are giving up to be part of the social network.

Four Corners is Australia's premier television current affairs program. It has been part of the Australian story since August 1961, exposing scandals, triggering inquiries, firing debate, confronting taboos and interpreting fads, trends and sub-cultures. Its consistently high standards of journalism and film-making have earned international recognition and an array of Walkleys, Logies and other national awards.