Summary Box: Google opens window on online piracy

ONLINE PIRACY INSIGHTS: Google has released data detailing the volume of complaints that the company's search engine has received about websites hosting content that violates copyrights.

BIGGEST TARGETS: There have been more than 2.5 million complaints sent to Google Inc. about websites believed to be infringing on Microsoft Corp.'s copyrights since July 2011, according to the report released Thursday. That's far more than any of the entertainment companies fighting for tougher laws against online piracy.

BIGGEST OFFENDERS: The websites spurring the most complaints logged by Google are: filestube.com (nearly 390,000 links requested for removal) and torrentz.eu (more than 147,000 links).