Societies have long sought security by identifying potentially dangerous individuals in their midst. America is surely no exception. Knowledge as Power traces the evolution of a modern technique that has come to enjoy nationwide popularity—criminal registration laws. Registration, which originated in the 1930s as a means of monitoring gangsters, went largely unused for decades before experiencing a dramatic resurgence in the 1990s. Since then it has been complemented by community notification laws which, like the "Wanted" posters of the Frontier West, publicly disclose registrants' identifying information, involving entire communities in the criminal monitoring process. Knowledge as Power provides the first in-depth history and analysis of criminal registration and community notification laws, examining the potent forces driving their rapid nationwide proliferation in the 1990s through today, as well as exploring how the laws have affected the nation's law, society, and governance. In doing so, the book provides compelling insights into the manifold ways in which registration and notification reflect and influence life in modern America.