Anwar al-Awlaki, the American imam who has become one of the world's best-known advocates of violence against the United States, was described by bombing suspect Antonio Martinez as "my beloved sheikh," according to the affidavit.
The 39-year-old Awlaki, who was born in New Mexico, studied at George Washington University and served as an imam in Falls Church, Va., is believed to have settled in Yemen. He communicates with followers via his website, Facebook page and YouTube videos.
He has never been accused of carrying out acts of violence himself, but he has been linked to others who have or have attempted to do so. Two of the hijackers in the Sept. 11 attacks are known to have prayed at Awlaki's mosque in San Diego.
Authorities say Awlaki exchanged e-mails with the Army major accused of killing 13 people at Fort Hood, Texas, last November and with the Nigerian man charged in the attempted bombing of an airliner that was headed for Detroit last December.
The Pakistani-American man accused of trying to set off a car bomb in Times Square in May also mentioned Awlaki.
The Obama administration has approved drone strikes against Awlaki. A lawsuit filed by Awlaki's father, who challenged the authority of the government to kill a citizen without trial, was dismissed this week by a federal judge, who ruled that the elder Awlaki did not have standing to sue the United States on behalf of his absent son.
The Syrian-born Omar Bakri Mohammad, now living in Lebanon, was among 24 people sentenced last month by a Lebanese military court to life in prison for terrorist activities.
Bakri has become infamous for statements supporting terrorism, including his interview in Britain in 2004 when he referred to the Sept. 11 hijackers as "the magnificent 19." He also made threats against Paul McCartney before he played a concert in Israel in 2008.
Martinez's Facebook "friends" included "Call to Islam," and "Authentic Tawheed," according to the FBI affidavit.
The affidavit describes "Call to Islam" as an "online movement" based in the United Kingdom and known to be affiliated with Revolution Muslim, identified in online sources as an Islamist group based in New York City.
Authentic Tawheed "appears to be a pro-jihad group," the affidavit says. A search for "Authentic Tawheed" turns up several sites, one of which seems to be devoted chiefly to discussion of the Quran. Tawheed is defined by the Oxford Dictionary of World Religions as "asserting the oneness of God, the supreme duty, and passion, of Islamic theology."