While IANAL, if you read the EFF brief & the judgement in depth, an interesting defense is being promulgated... Even if the defendants specifically allowed MediaSentry to download these files, as authorized agents of the copyright holders, no copyright infringement actually took place!!! There's case law that says that a copyright holder (or their agent) cannot infringe on their own copyright... Hence the new, stupid, "making available" claim...
What does that mean? Assuming this argument is valid (which I can't see how it couldn't be), the plaintiffs would have to go back to square one and find someone else on Kazaa who downloaded specific files from the defendants--specifically infringing on copyright law. And for anyone who has used P2P before, how often do you know (or remember) who you're downloading from? Personally, I think that borders on impossible to prove--unless Kazaa keeps some sort of detailed log data file that MediaSentry would have to gain access to...
The judge threw that argument out the window.
From the ruling "Amicus curiae, Electronic Frontier Foundation ("EFF"), responds that a copyright owner cannot infringe its own copyright, so its agent also cannot infringe the copyright owner's rights when acting on the owner's behalf. But the recording companies obviously did not intend to license MediaSentry to authorize distribution or to reproduce copies of their works. Rather, "the investigator's assignment was part of [the recording companies'] attempt to stop [Howell's] infringement," and therefore the 12 copies obtained by MediaSentry are unauthorized. "
-- Ravensfire