Record companies are trying to block Americans' access to a China-based website that allows free downloads of copyrighted songs.
Labels including Sony Music Entertainment, the Universal Music Group and RCA Records have filed the suit in Manhattan's Federal District Court.
The New York Times says the labels are acting against Listen4ever.com. Court papers say the site is "even more egregious" than Napster.
The labels hope to make ISPs block access to the site from the US. Reports say access was blocked by some providers on Saturday night.
AT&T Broadband spokeswoman Sarah Edler told the paper it's the first time it's been asked to block access to a foreign site.
The record labels say the free music site's domain name is registered to someone in Tianjin, east of Beijing.