http://www.bbc.co.uk/news/technology-19295221

Google might as well have said 'it's our job to police the net.' And even they must realise YT's next to useless without copyrighted material, so...

It is Google's duty to ensure as much ROI for their investors as they can. Constantly being sued by the media industry for "promoting" piracy through search results is not good for business.

If Google is getting regular take-down notices for certain sites from the courts, then they should demote them. The sites affected either need to dispute the orders or they need to change their business practices if they want a better Google ranking.

That said, I think Isohunt and Pirate Bay are right, most people who know what they are doing are going to search for torrents on Google.