has the host been  threatened by any terrorist group?
Yes - by Al-Qaeda
David Letterman
On August 17, 2011, it was reported that an Islamist militant had posted a death threat against Letterman on a website frequented by Al-Qaeda supporters, calling on American Muslims to kill Letterman for making a joke about the death of Ilyas Kashmiri, an Al-Qaeda leader who was killed in a drone strike in Pakistan in June 2011. In his show on August 22, Letterman joked about the threat, saying "State Department authorities are looking into this. They're not taking this lightly. They're looking into it. They're questioning, they're interrogating, there's an electronic trail—but everybody knows it's Leno."
what is just a girl? A song by American band No Doubt who created it? Gwen Stefani and Tom Dumont who was the vocalist of the song? Gwen Stefani has it been performed live anywhere? Yes - Virgin Megastore in Los Angeles, on the American TV show "Late Night with Conan O'Brien" , Late Show with David Letterman" what kind of show is the last one? An American late-night talk show hosted by David Letterman what are some of the notable episodes? Appearances by Regis Philbin, Marv Albert, Jack Hanna how is the episode structured? It opens with a series of shots of New York City as the CBS Orchestra performed the "Late Show" theme, the night's guests are announced, as well as Paul Shaffer and the CBS Orchestra, then introduced Letterman.
wiki:1590804
David Letterman [SEP] Al-Qaeda death threat
On August 17, 2011, it was reported that an Islamist militant had posted a death threat against Letterman on a website frequented by Al-Qaeda supporters, calling on American Muslims to kill Letterman for making a joke about the death of Ilyas Kashmiri, an Al-Qaeda leader who was killed in a drone strike in Pakistan in June 2011. In his show on August 22, Letterman joked about the threat, saying "State Department authorities are looking into this. They're not taking this lightly. They're looking into it. They're questioning, they're interrogating, there's an electronic trail—but everybody knows it's Leno."