A user posted the following message on a Web site (reputed to be Shumukh-al-Islam, according to EW.com) visited frequently by members of Al-Qaeda: "Is there not amongst you a Sayyid Nosair al-Masri (may Allah release him) to cut the tongue of this lowly Jew and shut it forever. Just as Sayyid (may Allah release him) did with the Jew Kahane." Sayyid Nosair al-Masri is an Egyptian-born man convicted of involvement in the 1993 World Trade Center bombing and tried for the assassination of Israeli politician Rabbi Meir Kahane, mentioned in the post.
The poster continued: “He showed his evil nature and deep hatred for Islam and Muslims, and said that Ilyas Kashmiri was killed and he joined bin Laden,” he wrote. “We ask Allah to paralyze his tongue and grant the sincere monotheists his neck."
The apparent joke in question was made back in June and referenced and/or mocked Ilyas Kashmiri, an accused terrorist leader who died in June following a U.S. airstrike in Pakistan.
According to an analyst for a group that tracks activity on extremist Web sites, the Letterman threat is more serious than the similar one made last year against South Park creators Trey Parker and Matt Stone after the show's depiction of Muslim prophet Muhammad.