what do you mean by "content contained within their own infrastructure"? I thought they forwarded the notices they get to chilling effects (and youtube ones are just posted in place of the video itself).
edit: this page http://www.google.com/dmca.html has about a 50/50 split across products between "may" and "will" be forwarded to Chilling Effects.
A quick search of term "xenu dmca" should show you come of the shit that google has to deal with in respect to the DMCA.
Any complaints about content on blogger, youtube or the adsense/adwords network get taken seriously and aren't forwarded on for the worlds entertainment.
edit: this page http://www.google.com/dmca.html has about a 50/50 split across products between "may" and "will" be forwarded to Chilling Effects.