diberry - 5:17 am on Apr 29, 2013 (gmt 0)
Uh, well, I keep my domains private because I'm a sole proprietor and don't want my legal name and home address splayed all over a page anyone can look up. That said, all my sites have contact forms AND the private WhoIs company I use has actual contact info, and anything you send them gets forwarded to me.
As I see it, the problem is not with the private registrations, but with hosts that don't take DCMA complaints seriously. You can pretty easily figure out who my hosts are from my WhoIs, and if you contact them to say I've done something wrong, they will be all over me. My hosts don't allow #*$!, let alone copyright infringement.
No, what Google needs to do is even more simple than what you describe. They just need to make the original publication date a stronger factor in the algo. If Bing can do it, I'm sure Google can.