This study researches the varying threats that emanate from terrorists who carry their activity into the online arena. It examines several elements of this threat. First, it explores elements of virtual to virtual attacks. Second, it looks at threats against critical infrastructures that can be traced to online sources. Third, this thesis reports on ways that terrorists are using information technology such as the Internet for propaganda and communication purposes. Finally, it highlights the most crucial ways in which the United States government has responded to the problem. It concludes with a few recommendations for best practices for future engagement with varying aspects of cyberterrorism.