December 13, 2016:
The U.S. believes that the August 2015 operation that killed ISIL (Islamic State in Iraq and the Levant) Internet expert Junaid Hussain in eastern Syria (Raqqa) did indeed cripple an ISIL Internet propaganda operation that had been key in getting the ISIL message on the Internet and keeping it there. This ISIL unit was unofficially known as "The Legion" and the U.S. has led an international effort to identify and capture or kill the key members of the Legion. The U.S. believes that the use of a UAV missile to kill Hussain broke the back of the Legion because ISIL was never able to find a suitable replacement for Hussain.
This may have had something to do with the way men like Hussain (Moslems raised in the West) were soon tracked down and killed. Since Hussain was killed least ten senior Legion leaders and technical experts were also killed or captured. That caused the Legion to fade away. All of the former Legion operatives were, like Junaid Hussain, trained in the technical aspects of the Internet (usually in the West) and able to use English (which some were raised speaking). Some of the key (and now deceased) Legion members began as hackers for hire or "hacktivists" eager to get their radical religious beliefs out to as many people as possible. Legion hackers also sought to obtain more information about American military personnel and use it to make personalized threats or help ISIL fans or members elsewhere in the world to kill specific people. The Legion was also seen as key in persuading so many Western Moslems to carry out (or make a serious effort to) "lone wolf" attacks. In short the Legion got noticed (and targeted) because their efforts were showing up as one of the reasons so many ISIL recruiting, fund raising and attack operations succeeded.