[Warning: Possibly Offensive Language Ahead]
On March 31st of 1994, a highly-charged Madonna appeared as a guest on the Late Show with David Letterman. Over the course of the now-infamous interview she said the word "fuck" a record thirteen times; called Letterman himself a "sick fuck"; asked the host to smell some underwear she was holding; refused to leave the stage when asked; and was jeered by the audience. Her behaviour resulted in numerous complaints, much discussion, and extremely high viewing figures.
A fortnight later, on April 12th - Letterman's birthday - Madonna faxed the following note to his office.
Transcript follows. Image courtesy of Julien's, who are selling the letter on the 27th of March.
Happy Fucking Birthday Dave!
glad you could get so much mileage out of the fucking show. Next time you need some Fucking publicity, just give me a fucking call.