According to an analysis of Google's weekly "transparency reports" performed by TorrentFreak editor ErnestoVan Der Sar, 51.5 million links to web pages allegedly infringing on copyrighted material were removed from search results in 2012.
"Nearly all of these web pages are no longer showing up in Google's search results," Van Der Sar reported.
Google, like any other website on the Internet, is obliged by federal law -- namely, the Digital Millennium Copyright Act -- to take down content when it receives a DCMA request from a copyright holder.
Van Der Sar noted that DCMA takedown activity has been increasing throughout the year, hitting a high point last week when Google received 3.5 million requests.
Much of that takedown activity is being fueled by automated systems used by large copyright holders. Those systems can be wildly inaccurate, which can lead to lawsuits.