Aug. 23, 2011 — -- How does a late night comedian respond a death threat from a radical extremist? With comedy, of course.
"Tonight, you people are more, to me, honestly, more than an audience... you're more like a human shield," CBS's "Late Show" host David Letterman said in his opening monologue to rounds of laughter Monday night. Letterman apologized for coming on stage late because he said he was going over CBS's life insurance policy "to see if [he] was covered for jihad."
The monologue was almost completely devoted to a death threat leveled against him last week, when an extremist wrote on the message boards of an Arabic website that American Muslims should "cut the tongue of this lowly Jew and shut it forever."
"I wish I had a nickel for every time a guy has threatened to cut my tongue out," Letterman said Monday.
The comedian, who is not Jewish, said the U.S. government was investigating the threat, but joked "everybody knows it's ['Tonight Show' host Jay] Leno."
Though the threatening post went up last week, it apparently was in reaction to a joke Letterman made in early June. Letterman had poked fun at the reported death of Mohammad Ilyas Kashmiri, the suspected leader of a Kashmiri militant group called Harakut-ul Jihad-i-Islami.
Letterman, known more for his comedic timing than his expertise on terrorism, said Kashmiri had taken over al Qaeda from bin Laden and ran the terror organization for a month before he was taken out in an American drone strike.
"Kashmiri lasted only a month on the job," Letterman said in June. "[Yankees star] Alex Rodriguez's girlfriends last longer than that."
ABC News' Martha Raddatz contributed to this report.