The RIAA used the DMCA to stop a research project that involved hacking a watermarking technology promoted by the five major record labels. A few good stories to read up on this issue:
Is the RIAA running scared? from Salon says this move by the RIAA \"shows just how wary of free speech the recording industry has become\", but, this case could potentially undermine the widely disparaged DMCA.
Similar Story at the NY Times.
Wired calls it Another Stain on Copyright Law. \"Once again, the law intended to promote the distribution of content on the Internet has instead been used to restrict it.\"