By all accounts, Warner Bros. new movie, “The Hangover Part II,” is a wild success on the road to becoming a box office blockbuster. Like the movie's premise, however, periods of euphoria can often lead to a painful hangover. What could cause Warner Bros.' hangover? Believe it or not, it's all about copyright law.

As was widely reported last week, Victor Whitmill, a Missouri “tattoo artist,” brought an action against Warner Bros. seeking to stop the Memorial Day weekend opening of “The Hangover Part II.” While District Court Judge Catherine Perry ultimately decided to let the movie open on schedule, Warner Bros. is not out of hot water. In fact, the comments Perry made at the injunction hearing should make Warner Bros. think about stocking up on Alka-Seltzer.

The dispute centers on a unique tattoo that Whitmill created for former heavyweight champion boxer Mike Tyson. Tyson appeared in the original “Hangover” movie sporting the tattoo, and “The Hangover Part II” features another character, played by Ed Helms, adorned with a tattoo similar to Whitmill's unique tattoo design. Whitmill argues that Warner Bros.' use of the tattoo design on Helms constituted copyright infringement. While the copyrightability of a tattoo may seem like a novel question, tattoo art certainly fits squarely within the definition of copyrightable subject matter.