If I understand the article correctly, it consumes processing power even when you're not playing CDs because it is constantly monitoring your computer:

"I closed the player and expected $sys$DRMServer’s CPU usage to drop to zero, but was dismayed to see that it was still consuming between one and two percent. It appears I was paying an unknown CPU penalty for just having the process active on my system. I launched Filemon and Regmon to see what it might be doing and the Filemon trace showed that it scans the executables corresponding to the running processes on the system every two seconds, querying basic information about the files, including their size, eight times each scan."

The author's conclusion:

"The entire experience was frustrating and irritating. Not only had Sony put software on my system that uses techniques commonly used by malware to mask its presence, the software is poorly written and provides no means for uninstall. Worse, most users that stumble across the cloaked files with a RKR scan will cripple their computer if they attempt the obvious step of deleting the cloaked files.

"While I believe in the media industry’s right to use copy protection mechanisms to prevent illegal copying, I don’t think that we’ve found the right balance of fair use and copy protection, yet. This is a clear case of Sony taking DRM too far."

If there's anyone who's more technologically sophisticate than I am (and that ain't hard), I'd be interested to hear how disturbing or dangerous you think this is.

• "Sony, Rootkits and Digital Rights Management Gone Too Far"