The Japan Society for Rights of Authors, Composers and Publishers searched YouTube, which was bought this month by Google in a share deal worth $1.65 billion, and found 29,549 files which infringed the rights of its members.
The files included television shows, music videos and films posted without the permission of 23 rights-holding companies. The group demanded that the files be taken down, a demand which YouTube met.
YouTube's policy has always been to take down copyright infringing material when notified that it breaches the rights of others, but requests have not always been on this scale.
Some observers believe that the company will attract the attention of rights owners through lawsuits because it is now owned by Google, but others believe the company does not have much to fear.
Kim Walker, a media lawyer with Pinsent Masons, the law firm behind OUT-LAW, recently told the weekly podcast OUT-LAW Radio that YouTube operates within the law.
"If YouTube is asked by content providers to take material down and doesn't do so within a reasonable period then it can certainly be liable for copyright infringement; otherwise it is primarily the user who uploads the material who will be liable," he said, adding that the company is operating entirely legally. "Unfortunately for the content holders that is currently the position."
YouTube has begun to negotiate deals with rights holders over licensed use of material. It has struck deals with record labels Universal, Sony BMG and Warner, as well as with US broadcaster CBS.
The Japanese rights society told the Associated Press news agency that it might ask YouTube to screen material before it is posted to the site, something which the site has not yet done. Reports have emerged, though, that YouTube is beginning to pre-screen material as part of its deal with record labels.
YouTube says that it shows 100 million video clips a day to the public, and that 65,000 videos are added to it every day.
