There is no doubt that fake news has become one of the key terms of 2017, brought into the spotlight after the US presidential election last November. It was soon clear thousands of people were unintentionally sharing articles full of misinformation. The resulting paranoia led people to accuse once-trusted sources, including The New York Times, of carrying fake news. Facebook is trying to do something about that. It is testing a new feature called the "i" button. When clicked, it gives the reader more information about the article they are reading. But Facebook admits it is not always easy to flush out fiction from fact.