Book excerpt: The Internet is used by internat. insurgents, jihadists, and terrorist org. as a tool for radicalization and recruitment, a method of propaganda dist., a means of commun., and ground for training. Although there are no known reported incidents of cyberattacks on critical infrastructure, this could become a tactic in the future. Contents of this report: (1) Background; (2) Why and How Internat. Terrorists Use the Internet: Propaganda, Recruitment, and Training; Cybercrime and Fund-Raising; Cyberattacks; (3) Fed. Gov't. (FG) Efforts to Address Cyberterrorism; FG Monitoring and Response; Counter-Propaganda: Strategic Commun., Public Diplomacy; DoD Offensive Response; (4) FG Challenges and Implications. This is a print on demand report.