It has been revealed that Stephanie Birkett, a former assistant to Letterman and friend/roommate of blackmailer Robert Halderman, was also a member of the extortion plot, though perhaps unknowingly. She is allegedly dismayed with Halderman for using her brief affair with Letterman as the basis for blackmail and the ensuing scandal.
We would be too. What is the painful, public message here? Never, ever, ever sleep with your boss. No matter how powerful/funny/mildly attractive they are.