When the news about David Letterman broke, my first reaction was that it showed how smart he is. Letterman managed to have the story that he was being blackmailed released in a way that he appeared as the victim. As more information came out, however, it became clear that he, at the very least, had misused his position and at the worst had committed sexual harassment.
Letterman apparently had several affairs with female members of his staff, while he was in a long-term relationship. He got married in the spring. The fact that he cheated on his partner is their business. Having sexual relations with workers who are your subordinates is sexual harassment. There is no way that there can ever be an equal, truly consensual, relationship. The worker is potentially subject to negative repercussions whether or not they have sex.
Does CBS have a sexual harassment policy? I am sure they do and I believe that their biggest star has violated it.