Rish3, I find sometimes you have to explain more in your DCMA request. I had a page that someone had PDF'd and random users were sharing it right and left, unaware they had no right to, in forums. I sent a DCMA for those forum pages and my guess is that Google sent a bot which couldn't read the PDF and therefore didn't see my text or images being stolen. I re-submitted, explaining that it was a PDF of my page, with all my text and photos, and they very quickly removed it from the index.
I would suggest you re-submit, this time explaining the proxy thing.
The problem is that the algo is failing to downgrade duplicates bigtime. I recall Matt Cutts or someone saying a while back that sometimes people would rather read the article from a more trusted source (again with this trust thing). That may be valid, but it's hardly CNN who's republishing our stuff. How are these spammer domains gaining "trust" over the sites that originally produced the content? Something's wrong in the algo. The stealing of content SHOULD weigh more than any trust factor, because it's a potential reason for people to stop trusting not just a domain, but a whole company. Imagine the PR problems if BigBoxCompany.com got caught stealing content. So it's not even in Google's best interest for the algo to reward content theft. For the life of me, I don't know why they do.