Access to government information in a post-September 11 often involves the resolution of conflicts between privacy rights and the public interest inherent in information flow. On the one hand, information about any individual investigated by the government, or merely landing in an investigative file, might very well invade the privacy of the detainees by unduly stigmatizing them. In fact, such reasoning reflects a line of argumentation central to the federal government’s justification for denial of access: privacy interests, particularly the risk of stigmatization. This chapter reviews the origins and expansion of stigmatization as grounds for protection of information under the FOIA. Examination of several key post-Reporters Committee cases decided by the federal courts illustrates the scope of the problem, as stigmatization has gained a great deal of legal traction in recent years.