1) Google algorithmically genreates take down notices on youtube, they move this over to search results.
2) Algorithms 'err on the side of caution' with regard to fair use.
3) Every page that quotes or excerpts a copyrighted work gets flagged.
4) So Google 'manually' makes exceptions for sites they strongly believe won't engage in poor behavior (NY Times, Techcrunch, whatever)
5) No new web site that reviews products or provides critical analysis ever makes it to Google's front page.
That might be a stretch, the auto-flag stuff on YouTube is out of control, and then trying to use that as a signal in results is just inviting abuse. Black hat SEOs are malicious enough without dealing with 'Copyright joejobs'
[ Full disclosure: I work at a search engine blekko.com ]