At first sight, Dirty Dancing and Titanic are two very distinct movies. However, if there were patents on story elements, then the makers of Dirty Dancing could have sued the studio of Titanic. Both movies have a scene in which a poor boy takes a rich girl from a party of her social peers to a dancing party of his group, and she enjoys it. Dirty Dancing came out only nine years before Titanic, so any patent would still have been in force. No one knows whether James Cameron had that Dirty Dancing scene in mind as he wrote the Titanic script. Maybe Cameron never saw Dirty Dancing but the patent (if it existed) could be used against him anyway.