Content_ed - 12:35 am on Dec 8, 2011 (gmt 0)
So I changed the first sentence of each paragraph on my page where different sections were stolen and widely syndicated a couple years ago. Also added one new paragraph to the top.
The next day, the page only appears in Google search for exact phrase from the new paragraph or the new sentences. For quotes from the rest of the page, Google mainly comes up with pages that no longer exist because I've DMCA's them out of existence.
In other words, the massive syndication of the stolen bits combined with the uusal number of whole page copyright infringements convinced Google that my page was some kind of mash-up or scraper, despite the fact it had hundreds of incoming links from the days before Google hated it.