Google and Facebook aren't fighting fake news with the right weapons

We know a lot about fake news. It’s an old problem. Academics have been studying it - and how to combat it - for decades. In 1925, Harper’s Magazine published "Fake News and the Public," calling it’s spread via new communication technoloies "a source of unprecedented dange." That danger has only increased. Some of the most shared "news stories" from the 2016 U.S. election - such as Hillary Clinton selling weapons to Islamic State or the pope endorsing Donald Trump for president - were simply made up.