Part I describes the American legal controls on the executive branch and their erosion after September 11. It addresses three changes incorporated in the USA PATRIOT Act: alterations to the Foreign Intelligence Surveillance Act, the introduction of Delayed Notice Search Warrants, and the expansion of National Security Letters. It highlights the Department of Defense's movement into the domestic surveillance realm. Part II focuses on the United Kingdom, noting that until recently no laws governed police and intelligence service information-gathering authorities. Exceptions are extraordinary stop-and-search powers for terrorist-related offenses and warrants for police interference with property. Part III identifies the substantive, political, legal, social, and economic risks posed by post-September 11 trends in executive power in America and the United Kingdom and then considers six approaches for mitigating these risks. One approach involves creating a property right for personal information. A second focuses regulating access, transfer, use, and retention of data. A third approach would scale back the existing powers of the state, and a fourth strategy would place limits on what constitutes national security. A fifth approach involves alternative safeguards and oversight structures, such as reporting requirements, random audits, the creation of ombudspersons, the insertion of the judiciary, and (in the United Kingdom) allowing intercepted communications to be used as evidence. A sixth approach would prevent countries from introducing ever greater powers of surveillance under the claim that they are only temporary, which would force legislatures to consider the long-term impact of provisions that extend beyond a perceived immediate threat. 758 footnotes