http://swissnet.ai.mit.edu/6805/student-papers/spring02-papers/caps.htm Abstract To improve the efficiency of airport security screening, the FAA deployed the Computer Assisted Passenger Screening system (CAPS) in 1999. CAPS attempts to identify potential terrorists through the use of profiles so that security personnel can focus the bulk of their attention on high-risk individuals. In this paper, we show that since CAPS uses profiles to select passengers for increased scrutiny, it is actually less secure than systems that employ random searches. In particular, we present an algorithm called Carnival Booth that demonstrates how a terrorist cell can defeat the CAPS system. Using a combination of statistical analysis and computer simulation, we evaluate the efficacy of Carnival Booth and illustrate that CAPS is an ineffective security measure. Based on these findings, we argue that CAPS should not be legally permissible since it does not satisfy court-interpreted exemptions to the Fourth Amendment. Finally, based both on our analysis of CAPS and historical case studies, we provide policy recommendations on how to improve air security.