A WMD, Weapon of Math Destruction, is an algorithm that is a block box (opaque), used at scale, and damages the lives of people, generally poor minorities. Cathy O'Neil goes through a lot of detail describing several of these WMDs and how they are ruining people's lives. Hate Clopening? (working at Closing and then Opening up the next morning). It's likely an algorithm created that schedule. Hate the fact that employers now use opaque personality tests to look for mental illness while you're applying for a job? Another WMD.

This book is important, and I think it should be read by anyone concerned about how Big Data can be used to harm us all. As someone whose future career depends upon algorithmic learning, statistics, and mathematics, I can say this book was eye opening. I'm used to hearing about the power of algorithms and modeling, but really, a model is not the thing that it models (as every mathematician knows).

This book is a lot more accessible than Derman's Models.Behaving.Badly, even if it is in the same vein. It has a much clearer focus, and it very clearly explains the traps mathematical modeling has created. I highly recommend this book to everyone. It doesn't require an understanding of math (there are no models or equations in this book). Just an understanding of how algorithms can contain bias through the use of proxies. Read it and share it.