With the accelerating process of globalization and the development of its technological dimension, more and more opportunities and channels are available to the terrorist groups in the world to mobilize resources and advocates. “Islamic State of Iraq and Sham” (ISIS), as the most modern terrorist-excommunicative group (Takfiry), has been able to utilize the Internet and social networks highly adeptly. While ignoring the function of long-term structural and essential factors underlying the formation of ISIS, and also combining the networked society theory and triple forms of identities proposed by Manuel Castells with theoretical discussions on identity making, networking, and mobilization of media, the current article seeks to analyze the role of cyberspace and social networks as accelerating and opportunistic agents in mobilizing resources and disseminating ISIS. Using an explanatory analytical research method, the current article mainly intends to find a reply to the question: What has been the role of online social networks in connection with ISIS as an excommunicative and terrorist group? According to the research hypothesis, due to ISIS’s subtle, prevocational-emotional and targeted utilization of online social networks, the networks have played the role of an accelerator and opportunity maker in some areas including network building, guidance of public opinion, identity making, and the promotion of project identity of this terrorist group. The general conclusion obtained from the article is that ISIS, as the most terrifying and the most modern group equipped with cyber media, has been able to attract many forces out of fanatical religious groups, unemployed people, criminals, etc., worldwide. Additionally, with the recruitment of fanatics, ISIS has been able to accomplish identity making and network building. As a result, regional security and even security in Western countries is also highly endangered.