The Recording Industry Association of America, the British Recorded Music Industry, and other industry lobbyists have sued one of the world's leading websites. They say that Youtube-mp3.org facilitates copyright infringement by enabling so-called stream-ripping for the masses.

Stream-ripping on YouTube-mp3.org essentially works like this: input a YouTube music video URL into a field on the site, press "convert video," and minutes later you have a fresh download of the music on the video.

The suit comes as the music industry is hoping that paid streaming services could fuel the resurgence of an industry that has barely grown the past five years. Youtube-mp3.org works using links YouTube Red, a paid service that strips ads. The RIAA, the BPI (the British equivalent of the RIAA), and other industry groups are none too happy about that. Youtube-mp3.org makes money via advertising on its landing page. Cary Sherman, chairman and CEO of the RIAA, said the following:

[Youtube-mp3.org] is raking in millions on the backs of artists, songwriters, and labels. We are doing our part, but everyone in the music ecosystem who says they believe that artists should be compensated for their work has a role to play. It should not be so easy to engage in this activity in the first place, and no stream-ripping site should appear at the top of any search result or app chart.

Youtube-mp3.org, which did not respond for comment, maintains that it copies the music to its own servers.

"Different from other services the whole conversion process will be performed by our infrastructure, and you only have to download the audio file from our servers," the site says on its landing page.

The industry said in its Los Angeles federal court lawsuit (PDF) that "Copyright infringement through stream-ripping has become a major problem for Plaintiffs and for the recorded music industry as a whole. From 2013 to 2015 alone, there has been a 50% increase in unauthorized stream-ripping in the United States."

Stream-ripping violates copyright law in many ways, the industry said.

In addition, on information and belief, YTMP3's unauthorized conversion, copying, storage, and distribution of Plaintiffs' copyrighted sound recordings is accomplished by YTMP3 unlawfully circumventing technological measures that YouTube has implemented to prevent the downloading or copying of content from the YouTube service. By engaging in and facilitating the unlawful infringement of Plaintiffs' sound recordings, YTMP3 deprives Plaintiffs (and other copyright owners) of the benefits of their investment in these valuable works and interferes with and creates a substitute for legitimate streaming and download services that are authorized by Plaintiffs.

The lawsuit—which comes two weeks after a survey found that about 50 percent of people aged 16-24 now stream rip—names Philip Matesanz as the site's owner and operator living in Germany. The site did not immediately respond for comment.

The suit says Youtube-mp3.org has "tens of millions of users and is responsible for upwards of 40% of all unlawful stream-ripping of music from YouTube in the world."

The suit seeks $150,000 (£115,000) in damages per infringement, the maximum amount allowed by US copyright law. It also demands that a federal judge shutter the site.

No hearing date has been set.