Muslim cleric Abdullah el-Faisal, and Pakistani-American Samir Khan as "virtual spiritual sanctioners" who use the internet to offer religious justification for Islamist terrorism. Authors Haroro J. Ingram and Jon Lewis describe Khan as an influential leader who employed his personal beliefs and values to influence his followers through his writing.

It was reported in May 2013 that Al Qaeda devotees native to the United States might have been using the instruction manuals that Khan posted online