Charlie Demerjian writes (rants?) in The Inquirer about Sony's DRM on music CDs. I'm not sure if calling the DRM a "rootkit" is appropriate. However, no matter how you brand it, it's invasive enough that removing it will kill your Windows installation.
Seems to me our choices in music are becoming more and more limited, at least as far as playing CDs on our computers goes. (They still work fine in dedicated CD players.) I, personally, have given up on CDs, though I love music. Seems as if every one I buy is unable to play on one or another device I own, because of the record company's fear that I'll steal something from them, thus cheating them out of money they can then cheat the artist out of.