Child Marriage and Dangerous Algorithms

Is a girl under the age of 15 married every seven seconds somewhere in the world? That is what the charity Save the Children claim in their attempts to raise awareness of child marriage. But how is this figure calculated? Data scientist and activist Cathy O’Neil wants to protect you from dangerous, and often hidden, algorithms.
In Nairobi one woman's online post about harassment on the city's private-hire minibuses or Matatus, has triggered dozens of similar accounts and complaints on social media of robbery, harassment and dangerous driving. We hear from the woman behind the #StopMatatuMenace hashtag campaign.
And can you believe your own eyes? Can you trust your own memory? Why is it that so many social scientists and so many in the police and the judiciary are so very concerned about eye-witness testimony. Mike Williams finds out why we often fail to accurately recall a face or an event.