The threat posed by a terrorist group is determined in large part by its ability to build its organizational capabilities and bring those capabilities to bear in violent action. Technology systems, meanwhile, play a key role within a larger, integrated homeland security strategy to target groups' efforts and protect the public from terrorist violence. technology systems designed to protect the public, actively seek ways to evade or counteract these systems. This volume examines a variety of terrorist groups - including Palestinian terrorist groups, Jemaah Islamiya and affiliated groups, the Liberation Tigers of Tamil Eelam, and the Provisional Irish Republican Army - to understand terrorists' countertechnology efforts. Fully exploring adversaries' countertechnology behaviors can expose vulnerabilities in U.S. defenses and help the nation make the best choices to protect it from the threat of terrorism. technologies as well as planning the technological components of homeland security efforts.