Google has unveiled plans to demote websites which have been given a valid copyright removal notice.
Senior vice-president of engineering at Google, Amit Singhal, said sites "with high numbers of removal notices will appear lower in our results".
"This ranking change should help users find legitimate, quality sources of content more easily," he said in a blog post.
Google received more than 4.3 million removal requests in July this year, part of an increasing number of copyright removal notices since "rebooted our copyright removals" in 2009.
The Motion Picture Association of America (MPAA) welcomed the search giant's move.
Senior executive vice president for global policy and external affairs, Michael O'Leary, said in a statement (pdf) that the rights holder organisation was optimistic Google's actions would help steer consumers to legitimate access methods for content, and away from rogue cyberlockers, peer-to-peer sites and others.
Danny Sullivan, of industry site Search Engine Land said it was "a necessary move by Google to get the entertainment dinosaurs to do more".
"At least they can't just keep blaming Google rather than their archaic distribution models," he said.
However, lobby group Electronic Frontier Foundation (EFF) criticised the move, saying it amounted to rights holders dictating search results.
"We wish we had some more details to illustrate just what that means, but unfortunately the process is pretty opaque," it said
"What we know: sites that have a 'high number of removal notices' of takedown notices that result in actual takedowns will show up lower in some search results, though they will not be removed. What we don’t know: what is a 'high number'?"
The lobby group said companies and site owners had no recourse if their site was demoted as a result of Google's new process, and warned the search giant could repeat mistakes made by the US Government in wrongly targetting sites that have the right to display the content.
The EFF argued takedown requests were "nothing more than accusations of copyright infringement".