For years, headlines about social media have been dominated by its adverse effects on society: From the virulent spread of misinformation, to the way your  data is tracked and mined. You would think that if users were so unhappy, they would just quit. But social media are engineered to be ‘addiction  machines’. Due to copyright reasons there is no podcast or stream for these lectures on the Big Ideas website. Please head to the CBC Massey Lecture website.