Nearly all communities are exclusive in some way. When race or wealth is the basis of exclusion, the homogeneity of a neighborhood, workplace, or congregation is controversial. In other instances, as with an artist's colony or a French language book club, exclusivity is tolerable or even laudable. In this engaging book, Lior Strahilevitz introduces a new theory for understanding how exclusivity is created and maintained in residential, workplace, and social settings, one that emphasizes information's role in facilitating exclusion. This book provides many colorful examples to show how lawmakers frequently misunderstand the subtle mechanics of exclusion, leaving enormous loopholes in the law. It explains that people create homogeneity not only by excluding undesirable outsiders via trespass law but also by manipulating these outsiders to exclude themselves. Strategic choices of a residential community's name, architecture, or amenities can dictate who will want to live there. To constrain fully a real estate developer's ability to create a homogenous community, the state would have to limit what he can say about the new community and second guess his decisions to embed amenities like golf courses, churches, or playgrounds inside it. The book concludes by examining how the dynamics of exclusion are changing in the twenty-first century. Search engines, social networking web sites, and consumer behavior databases have eroded personal privacy, increasing exclusion's precision. As decisionmakers gain more tailored information about individuals, they can place less reliance on crude proxies for behavior like race, gender, wealth, and age. Strahilevitz shows how these technologies present new opportunities for governments to stamp out the most offensive exclusionary behaviors. Lior Jacob Strahilevitz is deputy dean and professor of law at the University of Chicago Law School, where he has taught since 2002.