Attacks on computer systems for both criminal and political purposes are on the rise in both the United States and around the world. Foreign terrorist organizations are also developing information technology skills to advance their goals. Looking at the convergence of these two phenomena, many prominent security experts in both government and private industry have rung an alarm bell regarding the potential for acts of cyber-terrorism. However, there is no precise definition of cyber-terrorism under United States law or in practice among cyber-security academicians. The lack of a common starting point is one of the reasons existing law fails to directly address cyberterrorism. This paper furnishes a lexicon of cyber-related malicious activities and argues for a common working definition of cyber-terrorism. This definition can be both incorporated into current counter-terror legislation and used by government agencies to combat cyberterrorism. This paper arrives at that definition by analyzing the various definitions proposed by security experts and those in use by governmental organizations. This paper builds on these definitions to arrive at a new definition that is at once broad enough to cover the potentially unique effects of a weapon of cyber-terrorism, while narrow enough to exclude computer network attacks that are relatively minor in nature. Second, analyzing several recent cyber attacks, this paper finds that, while we have not yet faced a “cyber 9/11,” computer network attacks for political purposes are on the rise and becoming increasing complex. Third, this paper analyzes current law related to both cyber-crimes and terrorism, finding that while these laws are applicable in many instances, they fall short in adequately focusing on the most important factor when addressing cyber-terrorism: prevention. This paper concludes by recommending that cyber-terrorism, as defined in this paper, be incorporated into some of our most frequently used laws to combat terrorism.