The review of U.S. aviation security over the years notes that although issues remain to be addressed in specific risk areas such as cargo security and general aviation, the security of aviation today is significantly improved over what it was even 1 year ago. The downside is the direct cost of the security measures to taxpayers and airlines, as well as the indirect cost of inconvenience to airline passengers. The section of the chapter on the legal framework for aviation security discusses the authority of the Federal Government to regulate aviation security, the federalized screening process, the security responsibilities of private parties, international legal obligations, and privacy. The chapter concludes that the current aviation security system is constructed on solid legal grounds, so that it can withstand most legal challenges; however, the system is vulnerable to abuse in the form of discrimination against passengers, denials of due process when stopped from boarding for security reasons, and unreasonable invasions of privacy. These abuses will inevitably be potential problems with any security system due to human error, insufficient personnel training, and equipment failures. As security systems evolve, they must be constantly monitored for both effectiveness and adherence to existing law. 70 notes and discussion questions