Patently plotless
Patents on software are just as wrong as expanding the patent system to literature. With patents on story elements, no movie could be published without having to firstly check whether there is any general idea in the storyline that someone patented during the last 20 years. Here’s an example: 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.
From Thoughts Are Free! on No Software Patents!.