I had heard long ago about how Warner Brothers was upset about the then-upcoming 1946 Marx Brothers movie A Night in Casablanca because the studio was protective of their own 1942 film Casablanca. It turns out that the story I heard was not what really happened. Groucho Marx did write a series of hilarious letters responding to Warner Brothers' request for information, but they were all part of a publicity stunt that paid off well for the Marx Brothers' movie. Letters of Note has one of the responses that Groucho wrote:
Read all three pages at the post. Link
I just don't understand your attitude. Even if they plan on re-releasing the picture, I am sure that the average movie fan could learn to distinguish between Ingrid Bergman and Harpo. I don't know whether I could, but I certainly would like to try.
You claim you own Casablanca and that no one else can use that name without their permission. What about Warner Brothers -- do you own that, too? You probably have the right to use the name Warner, but what about Brothers? Professionally, we were brothers long before you were. When Vitaphone was still a gleam in the inventor's eye, we were touring the sticks as the Marx Brothers and even before us, there had been other brothers -- the Smith Brothers; the Brothers Karamazoff; Dan Brouthers, an outfielder with Detroit; and "Brother, can you spare a dime?" This was originally "Brothers, can you spare a dime" but this was spreading a dime pretty thin so they threw out one brother, gave all the money to the other brother and whittled it down to "Brother, can you spare a dime?"
Read all three pages at the post. Link