It is sometimes believed that the open source movement and copyright are incompatible. In fact, the open source community relies on effective copyright protection to support its licensing model.
A case in point is Jacobsen v Katzer. In a landmark decision last year, 535 F.3d 1373 (Fed. Cir. 2008), the US Federal Circuit Court of Appeals (CAFC) decided that failure to comply with the conditions terms of the Artistic License could lead to copyright infringement. The CAFC remanded the case back to the district court to consider whether there was infringement on the facts of the case.