As detailed by the BBC, Blizzard's latest version of WoW installs a spyware program known as The Warden. In addition to monitoring a player's system for any known cheating or trainer software, The Warden also scans the title bars of any other running program, and is capable of retrieving email addresses or open URLs.
Obviously this is the sort of development some players or potential players won't be happy about, but there's an ironic twist to the story. Apparently, Sony's rootkit can be used to deactivate Blizzard's monitoring software, as discussed here. Not only is there a certain hilarity in using the spyware from one company to break the spyware from another, but this rather unintended use punches a large hole in Sony's DRM FAQ. From their website:
6. I have heard that the protection software is really malware/spyware. Could this be true?
Of course not. The protection software simply acts to prevent unlimited copying and ripping from discs featuring this protection solution. It is otherwise inactive. The software does not collect any personal information nor is it designed to be intrusive to your computer system. Also, the protection components are never installed without the consumer first accepting the End User License Agreement.
I think Blizzard might disagree.