An Islamic State fighter holds holds a rifle and the group's flag shortly after capturing the northern Iraqi city of Mosul in June 2014. Dozens of Americans have been accused of planning or heading off to the Middle East to join the group. Their individual cases are on the chart below. Reuters/Landov hide caption

itoggle caption Reuters/Landov

A member of Iraq's government forces battling Islamic State fighters in Anbar province earlier this month. Haidar Hamdani/AFP/Getty Images hide caption

itoggle caption Haidar Hamdani/AFP/Getty Images

Haqqathon-ers from the winning team, which developed the social media site Champions of Islam, at the event in Abu Dhabi, United Arab Emirates. Courtesy of Rim-Sarah Alouane hide caption

itoggle caption Courtesy of Rim-Sarah Alouane