If you play World of Warcraft, you might want to avoid a life of crime because, although you think you are anonymous online, you aren’t. Making matters worse, Blizzard will hand your information over to the authorities in a heartbeat.
Blizzard did more than cooperate. It gave authorities everything needed to track a fugitive down including his IP address, account information and history, billing address, and even his online screen name and preferred server. Source Kokomo Prospective