Terrorists are using the Internet for various purposes. Most of the attempts to monitor and study terrorist presence on the Net focused on the practical and communicative uses of this channel by modern terrorists. Yet, not much attention has been paid to the use of the Net as a medium for terrorist debates and disputes. This descriptive article presents this less noticed facet of terrorism on the Net by providing examples of virtual debates among and within terrorist groups. The analysis of the online controversies, disputes, and debates may say a lot about the mindsets of terrorists, their motivations, their doubts and fears. In many ways, it allows the researcher to open a window to a world about which so little is known. It may also serve counterterrorism: by learning the inner cleavages and debates one can find practical ways to support the voices against terror, to broaden gaps within these dangerous communities, and to channel the discourse to nonviolent forms of action.