Nigel Carson, a computer forensics investigator from KPMG, said Wednesday during a trial in Australia's federal court that it is possible to locate the physical computer and user of the machine by tracing the IP address. He said that IP addresses usually change when a dial-up connection is involved. However, most of the time, users with broadband and cable Internet connections use only one IP address.
Carson added that even when IP addresses change, the user can still be tracked down to the Internet service provider where the person's information can be collected.
Carson said that if a company like Sharman Networks wants to trace a specific user who shared unlicensed music files, it would need to store the date and time that the transaction was done.
However, he said that companies usually need a legal order before they can obtain user information from an Internet provider. Carson also admitted that he saw a copyright warning before he himself downloaded the Kazaa software.
When questioned by Tony Bannon, a lawyer representing the music industry, Carson said he was not familiar enough with the Kazaa software to be able to answer if it has so-called remote trigger capability, which allows an organization to terminate a user's connection. But he said that type of technology exists.
The morning was taken up by legal arguments on what evidence proposed by the applicants is admissible in court. Justice Murray Wilcox declared some passages of the affidavits as inadmissible because of lack of evidence or lack of relevance to the case.
Kristyn Maslog-Levis of ZDNet Australia reported from Sydney.