IP Addresses Not Enough To ID Users

phaedrus5001, with his first accepted story, points out an article at Ars Technica from which he's excerpted a chunk relevant to nearly anyone with an internet connection: "A file-sharing lawyer admitted this week that IP addresses don't by themselves identify someone accused of sharing copyrighted material online. To figure out who actually shared the pornographic movie at the center of the case, lawyer Brett Gibbs of Steele Hansmeier LLC told the judge (PDF) he would need to search every computer in the subscriber's household."