Facebook Data Breach: US Congress grills Mark Zuckerberg on data leak

Facebook boss Mark Zuckerberg has told US lawmakers that he's "sorry" for allowing the data of millions of people to be improperly used by the political firm Cambridge Analytica. In his first public appearance before Congress, Mr Zuckerberg acknowledged his company had to do more to crack down on the spread of fake news and foreign interference in elections. Harry Horton reports.