“Weapons of Math Destruction” is the Big Data story Silicon Valley proponents won’t tell. The author, Cathy O’Neil, is a former academic mathematician and ex-hedge fund quant at D.E. Shaw, once part-owned by Lehman Brothers. Her book pithily exposes flaws in how information is used to assess everything from creditworthiness to policing tactics, with results that cause damage both financially and to the fabric of society. O’Neil had an epiphany in the aftermath of the 2008 financial crisis: mathematical models were “not only deeply entangled in the world’s problems but also fueling many of them.” A convert’s passion runs through the book as the author explores how math can flip over to the dark side. Flawed algorithms, applied widely, become the WMDs of the title.