Some links to complete the backstory:
Quest for the Perfect Pitch
If in fact DMCA take-down has been used for SEO gains, than I hope my small contribution to Adactio's perfect pitch quest is helpful.
So let’s get this straight. In a discussion about perfect pitch, someone mentions the website perfectpitch.com. They don’t repost any materials from the site. They don’t even link to the site. They don’t really say anything particularly disparaging. But it all takes is for the owner of perfectpitch.com to abuse the Digitial Millenium Copyright Act with a spurious complaint and just like that, Google removes the discussion from its search index.
Adactio Post 1623 - Perfect Pitch