After I made my previous post I was pondering what Viacom hops to win in this case. The obvious thought is that they want to gut the DMCA safe harbor, but this seems like it would make combating piracy harder in the long run.

The safe harbor is the carrot offered so that service providers respond to DMCA takedown notices. Without that carrot, or with it much farther away, service providers are less likely to cooperate with Viacom.

Viacom is setting the playing field for service providers like this: 1. Dedicate resources to DMCA takedowns and then spend millions defending your safe harbor status anyway, or 2. Spend millions in copyright fines

This is a bad playing field to set, the DMCA takedown is a pretty sweet deal for Viacom. Why spoil it by making option 2 so attractive to service providers? And then option 3 dawned on me:

3. Don't allow user content

I don't think this case is really about copyright at all. It seems to me that Viacom's real goal is just to squash a competitor using the courts.