I think it supports their claim for safe harbour under DMCA. To invoke "safe harbour" I think you need to show that it would be unreasonably difficult to polic

I think it supports their claim for safe harbour under DMCA. To invoke "safe harbour" I think you need to show that it would be unreasonably difficult to police the content yourself. Google already has a good argument for that, but it strengthens it if they can show that Viacom is also uploading to YouTube in a legal yet indistinguishable (to YouTube) way to the people it claims are infringing.