Broken Piano for President is a blog and eponymous book by Patrick Wensink. The book’s cover, at left, bears a resemblance to the label on a bottle of Jack Daniels Whiskey.
In addition to its great tone, the letter explains why trademark law forces mark-holders to send C&D letters: if mark-holders don’t police unauthorized uses of their mark, they can lose rights in the mark. This is because one factor courts consider is whether the trademark owner zealously polices its mark. As explained by the Second Circuit:
[O]nce a trademark owner loses control of its mark by failing zealously to watch over its use by others — or by not objecting to its unauthorized use — the reputation associated with the mark is reduced.
Church of Scientology Int’l v. Elmira Mission, 794 F.2d 38 (2nd Cir. 1986)
C&D letters aren’t sent for the sake of more litigation. They are sent because mark-holders who don’t send them tend to weaken or lose rights in their mark. Mark owners can use such letters in later litigation to help demonstrate that they actively police unauthorized uses in their marks.