ISIS in America: From Retweets to Raqqa, by Lorenzo Vidino and Seamus Hughes, George Washington University’s Program on Extremism, December 2015.

“Searching for Answers – What explains the recent surge in American jihadi recruits? Who are the Americans lured by the siren songs of ISIS’s propaganda? How do they embrace such radical ideology, turning their backs on their country and, in most cases, their families? Do they do so by themselves or in clusters of like-minded individuals? Once radicalized, what do they seek: to join the ISIS caliphate between Syria and Iraq or to carry out attacks in the U.S.? Answers to these and related questions concerning ISIS mobilization in the U.S. have puzzled authorities and the public alike. To shine new light on them, the staff at the George Washington University’s Program on Extremism engaged in a six-month study of the recent surge in domestic radicalization. The result is this report, which, while unable to examine every aspect of such a complex and fluid phenomenon, provides a comprehensive overview of ISIS-related radicalization and mobilization in the United States. The report consists of two parts. The first examines all cases of U.S. persons arrested, indicted, or convicted in the United States for ISIS-related activities since the first case in March 2014. A wide array of legal documents related to these cases provides empirical evidence for identifying several demographic factors related to the arrested individuals. This section also looks at the cases of other Americans who, while not in the legal system, are known to have engaged in ISIS-inspired behavior. The second part of the report examines various aspects of the ISIS-related mobilization in America. Here the report analyzes the individual motivations of ISIS supporters; the role of the Internet and, in particular, social media, in their radicalization and recruitment processes; whether their radicalization took place in isolation or with other, like-minded individuals; and the degree of their tangible links to ISIS..”