Only certain sites are removed from Google results, the key words haven't been blacklisted so you can still search on them and get hits. It's not the first time Google's bent over either,
http://www.chillingeffects.org/dmca512/notice.cgi . I guess it's just not in their business interest to defend these; they get served a DMCA notice, and as a service provider they follow it to remain within the safe harbor provisions.