I found this article in the Daily Howler via Rhetorica.

Even though Bob Somerby discusses conservative bias, if you read the information presented another kind of bias comes out, perhaps even worse. Favoritism for candidates who are friendly to reporters. This could be even more dangerous than it seems at first glance. Our intelligence agencies know they are going to miss something sooner or later, and there will be stories about it in the media. Who will get more than their share of blame, and who will get less? And have you seen any information in the media from unnamed officials about how we decide the alert color of the day which could possibly be useful to terrorists trying to evade our intelligence, and what did the unnamed officials hope for in exchange? Not money I'm sure, that would be unethical. But if errors are made, perhaps the story will be slanted just slightly differently if some people have been more helpful than others to the media.