The Islamic State, the radical group which has cut a bloody path through Syria and Iraq in recent months, slaying civilians and security forces, and executing the American journalist James Foley on camera, has even more followers than previously believed, according to Iraqi security sources.
While western diplomats and other observers have estimated the number of militants number between 20,000 to 50,000, Hisham al-Hashimi, a security expert in Baghdad, said that the total membership of the Islamic State in Iraq and Syria may now be closer to 100,000 members.
http://mashable.com/2014/08/26/100000-people-join-islamic-state/