Just so we understand, Google/YouTube formulates a privacy policy, users function under the assumptions that the policy is in effect, one or more YouTube users upload copyrighted content, and, just like magic, your rights disappear.

It's one thing to turn over records of users who viewed specific content but kind of blanket sweep is not required. If this kind of ruling stands you can kiss any sense of privacy goodbye. Where does this overreach end? Will someone simply have to claim that someone else on a site you used did something to violate the their rights and the service provider will have turn over their logs?

I for one am looking forward to the day when balanced, reasoned responses to these kind of question come back in vogue.

UPDATE: Google/YouTube lawyers have managed to protect some measure of privacy according to the YouTube blog. The court opinion on this matter indicates the log data will be scrubbed of key personally identifying information but will still maintain unique but anonymous identifiers:

When producing data from the Logging Database pursuant to this Order, Dependents shall substitute values while preserving uniqueness for entries in the following fields: User ID, IP address, and Visitor ID. ... and preexisting interdependencies shall be retained in the version of the data produced.

This should allow Viacom to see that John Doe 2,314,873 did in fact watch 7 South Park episodes and an MTV video last year on YouTube. It could also allow them to discern other patterns in the data that have nothing to do with their content and that is still a problem.