Supporters of the al-Nusra Front protest in Aleppo, Syria, on Sept. 26, days after airstrikes there targeted the al-Qaida unit called Khorasan. U.S. officials say some top Khorasan leaders were embedded with the Nusra Front, al-Qaida's arm in Syria. Fadi al-Halabi/AFP/Getty Images hide caption

itoggle caption Fadi al-Halabi/AFP/Getty Images

Sheik Abdullah bin Bayyah is interviewed about his fatwa explaining why ISIS is wrong to claim that Islam supports violence and the establishment of a caliphate by force. Dina Temple-Raston/NPR hide caption

itoggle caption Dina Temple-Raston/NPR

Lt. Gen. William C. Mayville Jr., Joint Staff Director of Operations, speaks about airstrikes in Syria during a briefing at the Pentagon yesterday. Brendan Smialowski/AFP/Getty Images hide caption

itoggle caption Brendan Smialowski/AFP/Getty Images

This image, posted on a militant website, shows an Islamic State fighter waving a flag from a captured government fighter jet in Raqqa, Syria. The group is well-funded and has gained territory over the past few months; that's raised some concerns in America, although experts say the organization is largely focused on regional goals. AP hide caption

itoggle caption AP

American Eric Harroun threatened Bashar Assad on Facebook and YouTube. He spent six weeks fighting with a rebel army, a journey that did not end well for him. ABC News/YouTube hide caption

itoggle caption ABC News/YouTube

This photo provided by The Guardian in London shows Edward Snowden, who worked as a contract employee at the National Security Agency, in Hong Kong last year. AP hide caption

itoggle caption AP