I think it’s better to write to the sponsors. I don’t want the FCC to be deciding what comedians say. They might decide that Jeff Dunham (”Silence! I keel you!”—Achmed the dead terrorist) could say.
While I agree with you - I think we need to hit CBS, Letterman show sponsors AND the FCC. Decent Americans drove Dan Rather off TV - we can do the same to a vile scum such as Letterman.