A playground is seen in London, outside an address where Kuwaiti-born London computer programmer Mohammed Emwazi is believed to have lived. Emwazi has been identified as masked ISIS militant "Jihadi John." Niklas Halle'n/AFP/Getty Images hide caption

itoggle caption Niklas Halle'n/AFP/Getty Images

Somali-American youths play basketball before the start of a September 2013 solidarity rally by the Minneapolis Somali community to denounce al-Shabab's attack of a shopping mall in Nairobi, Kenya. Less than a decade after groups of teens from Minneapolis emigrated to Somalia to join the terrorist group, more have been recruited to join the self-declared Islamic State in Syria. Eric Miller/Reuters/Landov hide caption

itoggle caption Eric Miller/Reuters/Landov