Ana and John Conley, parents of defendant Shannon Conley, exit the U.S. Federal Courthouse in Denver following their daughter's plea hearing on Sept. 10. Shannon Conley, 19, pleaded guilty on a charge that she intended to wage jihad. Brennan Linsley/AP hide caption

itoggle caption Brennan Linsley/AP

The Express newspaper reported that U.K. officials have intelligence suggesting al-Qaida has been planning a high-profile attack on five commercial flights sometime before Christmas. Mark Wilson/Getty Images hide caption

itoggle caption Mark Wilson/Getty Images

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