When I filed a DMCA with Adsense (a different site from the one I pointed above), Adsense wanted me to show proof that I have sued the other party before they remove them from Adsense. This site copied word for word several of our articles (which so happen to be our top money makers), and then claimed the authorship as their own (they put their byline in the article, and removed my name.
We are providing you with the counter notification and await your notice (in not more than 10 days) that you have filed an action seeking a court order to restrain the counter-notifier's allegedly infringing activity. If we do not receive such notice from you, we will not remove the AdSense publisher from our program.
I had to drop the claim because I was not willing to spend money on a lawsuit. Such a shame.