The way I see it is that it wouldn't cost much or take much effort to get that message to Osama so why not do it? It certainly calls his bluff and would be quite effective.
True. And yet I remember Tom Tancredo being left to twist in the wind when he made mention of glassing Mecca if the U.S. were ever hit by a dirty bomb courtesy of al Qaeda. Tancredo's remarks were the only thing that ever got through to the Islamists across the world, and he was condemned throughout the nation by the appeaseniks and RINOs.