Check out http://arstechnica.com/news.ars/post/20050519-4925.html. I quote my favorite part
The plaintiffs do not know the identity of the persons they wish to sue, let alone the details of precisely what was done by each of them such as to actually prove infringement. Such facts would only be established after examination at trial. […] It is sufficient that they show a bona fide claim, i.e., they they really do intend to bring an action for infringement of copyright based on the information that they obtain, and that there is no other improper purpose for seeking the identity of these persons.
Nevertheless, the court found IP addresses deficient as a justification for forced identification, and they rejected the argument that the broadband companies were in possession of documents detailing who these users are in real life. With regards to this latter issue, the court rightly noted that matching an IP at any given time to a user constitutes more than re-producing information (e.g., there’s no peice of paper they could surrender; rather, they’d have to investigate themselves). Along similar lines, the court said that the evidence presented amounted to nothing more than hearsay. As you can see, the gist of the decision centers not on ideology or copyright analysis, but on the rules of evidence.
This is really interesting. I’m specially impressed by the notion that when an ISP gives information about a user based on the IP address, the court compares this to hearsay.
Of course, this was in a Canada court, and I don’t think that we’ll see something like this in Portugal anytime soon.