On September 16, 2016, Social Science Matrix hosted Cathy O'Neil, author of *Weapons of Math Destruction: How Big Data Increases Inequality and Threatens Democracy. *In her book (and presentation), O'Neil—a Harvard-trained mathematician and former hedge fund data analyst—discusses how many of the decisions that affect our lives—where we go to school, whether we get a car loan, how much we pay for health insurance—are being made not by humans, but by mathematical models. The problem, she explains, is that they are often WMDs—widespread, mysterious, and destructive—making them "Weapons of Math Destruction."