A German court ruled Friday that YouTube must install filters to prevent users uploading some music videos whose rights are held by a music-royalties collecting body.

Hamburg's state court sided with Germany's GEMA, which had sued Google Inc.'s YouTube unit over 12 temporarily uploaded music videos for which no licensing fees were paid. The organization represents about 60,000 German writers and musicians.

The online video platform has maintained that it bears no legal responsibility for the uploaded content — saying it checks and sometimes blocks content when users alert the firm about alleged violations of laws.

YouTube currently offers copyright holders software that allows them to identify recordings for which they hold copyright, enabling them to flag the content as infringing their rights.

The Hamburg court ruled that once an alleged violation is flagged YouTube must now apply the software to the recording to prevent further copyright infringements.

The court also told YouTube to install a new program that filters uploaded videos for possible copyright infringements according to key words — such as musicians' names and song titles — to catch versions of a song that only sound somewhat different, such as live recordings.

"The platform operator only has the obligation to block the video ... and take appropriate measures to hinder further rights violations after being notified about the copyright violation," the court said. "There is no obligation to control all videos already uploaded to the platform," it added.

Kerstin Becker, a GEMA attorney, said the verdict is "a great success for GEMA" because it made clear that YouTube bears some legal responsibility for videos uploaded by its users, German news agency dapd reported.

But Google spokesman Kay Overbeck said the ruling was only a "partial success" as the court made it clear that YouTube is a platform hosting external content.

In its ruling, the court said it does not consider YouTube the copyright violator, but the user who uploaded the song.

It argued that YouTube therefore bears only limited responsibility for the content, thus sparing it from having to check all videos for copyright infringements — which would "make its basically legal business disproportionately more difficult."

It was not immediately clear if the ruling will be appealed.