IANAL, but copyrights also differ from patents in that you have to show intentional imitation, not just similarity. Since prior art would reasonably prove that

IANAL, but copyrights also differ from patents in that you have to show intentional imitation, not just similarity. Since prior art would reasonably prove that couldn't have copied something, this would imply that this avenue of defense is strictly stronger than the prior art defense against patent litigation. Some quotes from Wikipedia (with the usual caveats): > "... two authors may own copyright on two substantially identical works, if it is determined that the duplication was coincidental, and neither was copied from the other." > "Infringement requires... that the defendant copied the protected work... if two individuals both create a story that by pure coincidence is nearly identical, but each without knowledge of the other, there is no infringement since there is no copying."