Understanding how terrorists conduct successful operations is critical to countering them. Terrorist organizations use a wide range of network technologies as they plan and stage attacks. This book explores the role that these communications and computer technologies play and the net effect of their use, the purpose and manner in which the technology is used, the operational actions of terrorists and possible responses of security forces. The authors conclude that future network technologies modestly improve terrorist group efficiency, particularly for their supporting activities, but do not dramatically improve their attack operations. Precluding terrorists from getting the technology they want is impractical; developing direct counters is unlikely to yield high payoffs. Instead, exploiting the technologies and the information such technologies use to enable more direct security force operations are more promising options.