In 2007, Stephanie Lenz put a 29-second clip of her baby dancing on YouTube. If you listened closely, you might have identified the music in the background. It’s the song “Let’s Go Crazy” by Prince. Once the video was online, Universal Music cried copyright infringement and the video was taken down. Lenz filed a lawsuit arguing that her video was protected by fair use, and that lawsuit has become one of the most infamous in modern copyright law. Yesterday, the Ninth Circuit Court of Appeals in San Francisco basically found that she has enough of a case to go to trial.