A number of folks have been pointing out this article that argues that the movie industry get’s it while the record industry doesn’t. That maybe. But, it may also be that the real difference is that a digitized movie is a lot larger than a digitized pop song. It might be because the movie industry managed to get at least a modicum of digital rights management into the DVD standards. Boths these certainly limit the moblity of the bits and gives the movie mogels more time to resolve their problems.
But I think the real difference is that CD writers are standardized and very common, while DVD writers remain a standardization mess and so they remain rare.
It maybe that the success of the movie industry in this game arises entirelfrom their success at delaying the standardization of writable DVDs.