All three major labels — Universal, Warner and Sony — have filed a lawsuit in Califionia federal court against a German YouTube stream ripping website, which allows users to convert YouTube videos to mp3 format.
In a report published by Billboard, the labels claim that stream ripping "has become a major threat to the music industry, functioning as an unlawful substitute for the purchase of recorded music and the purchase of subscriptions to authorized streaming services."
The accused, YouTube-mp3.org, is said to be the "chief offender, accounting for upwards of 40% of all unlawful stream ripping that takes place in the world."
Claims of several different types of copyright infringement are being brought against YouTube-mp3.org, with the lawsuit demanding access to the site be blocked and the company pay forb statutory damages and costs.
You can read the full complaint document here.