Schneier on Security: Blizzard Entertainment Uses Spyware to Verify EULA Compliance

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According to the World of Warcraft terms of service, when you install the latest version of the game, an anticheat program called Warden snoops through your entire computer looking for "unauthorized third-party programs" that allow users to "hack" or "modify" the online game environment or "cheating of any kind."

You signed up for it, you agreed to it, and it isn't sending anything bad yet.

However, they are owned by Vivendi Universal, not a company that I have the greatest respect for. And I do think that their efforts to use the DMCA to prevent reverse engineering of the Battle.net protocols to stop people from running their own b.net servers is yet another bad example of inappropriate copyright enforcement that denies me the right to analyse traffic flowing over my own network.