This book explores the use of Social Security Numbers (SSN) and Identity Theft. The SSN was created in 1936 for the purpose of tracking workers’ earnings for benefits purposes. Since that time, however, SSN usage has expanded to encompass a myriad of purposes well beyond the operation of the Social Security system. This book describes how criminals acquire SSNs and how they use them to commit identity theft. How organizations such as financial institutions, insurers, universities, health care entities, government agencies, and innumerable other organizations use this nine-digit sequence as a default identifier is also examined. Furthermore, existing statutes, regulations and private sector efforts designed to protect SSNs are looked at, including data security and data breach notification laws. This book concludes with specific FTC recommendations, which address both the supply and demand aspects of the SSN problem by proposing actions that would make SSNs less available to identify thieves, and would make it more difficult for them to misuse those SSNs they are able to obtain.This is an edited, excerpted and augmented edition of a Federal Trade Commission and GAO publication.