SunnComm's "advanced copy protection mechanism", called MediaMax CD3, actually simply had the autorun.ini added to the audio CD. This auto-ran then a small installer that installed a driver which claimed in its EULA text to be necessary in order to use the CD under Windows operating system. In reality, the driver itself was the entire copy protection.
So, Halderman's big finding was that the copy protection can be "bypassed" by holding down the shift-key when inserting the CD in a CD-ROM -drive. As most Windows-users already know, the shift-key instructs Windows to ignore the AutoRun feature found on the disc. When the autorun-feature is skipped, the driver installer never runs.
Now, SunnComm claims that Halderman's findings and the fact that he published his findings, have damaged SunnComm's market value by at least $10M and that he has violated against the DMCA law that makes it illegal to distribute instructions and tools that would allow circumventing copy-protection mechanism (as Linux doesn't launch autorun.ini anyway, does it mean that Linux is a tool that allows breaking the law as well?).
SunnComm stated: "SunnComm intends to refer this possible felony to authorities having jurisdiction over these matters because: 1. The author admits that he disabled the driver in order to make an unprotected copy of the disc's contents, and 2. SunnComm believes that the author's report was 'disseminated in a manner which facilitates infringement' in violation of the DMCA or other applicable law".
More information:
CBC
The Register