Here's an interesting case highlighted by Eric Goldman, involving two competing software companies. One of the companies, Real View, downloaded an infringing copy of the other company's (20-20 Technologies) software via a file sharing network. It seems this part is not contested. Real View then used the software to learn about what 20-20 was offering, and modified its own software to include some similar features, and then used a different business model which undercut 20-20's business model quite a bit. 20-20 sued for infringement both over the download and over the software. The jury, quite reasonably, said that the new software didn't violate anyone's copyright, as reverse engineering similar features to a competitor is not infringement. However, since the initial download was infringing,...