The U.S. Supreme Court refused Monday to consider whether a Texas woman who was sued for downloading music illegally can argue that she was too young and naive to know she was violating copyright laws.

Several record companies, including Warner Bros. Records Inc. and Sony BMG Music Entertainment, sued Whitney Harper in 2007 for illegally downloading music on Internet file-sharing networks. A federal judge ruled the companies were entitled to collect damages from Harper for illegally downloading 37 copyrighted songs.

The record labels sought a minimum $750 penalty for each song, as provided by the federal Copyright Act. Harper, however, sought to trigger the "innocent infringer" provision of the act, which allows for penalties as low as $200 per violation if the defendant had no reason to believe her acts constituted copyright infringement.

Harper, who acquired the songs when she was a 16-year-old, said she did not realize she was downloading the music, thinking instead that file-sharing networks were similar to Internet radio stations.

The record companies said Harper was a "long-term, massive infringer" of their copyrights.

The companies argued, and a federal appeals court agreed, that Harper could not assert the innocent-infringer defense because the companies had clearly placed copyright notices on the CDs of their musical recordings.

The Supreme Court let the appeals court ruling stand.

Harper had argued that the copyright notices placed on CDs were irrelevant in the digital setting, where the music files contained no copyright notice. She warned that a win for the record labels would mean that downloading music on the Internet could never be deemed innocent infringement.

The record companies said they have "transitioned away" from suing individuals for infringement, preferring other mechanisms to stop music piracy. They said Harper's case was one of very few still working their way through the federal courts.

The case is Harper v. Maverick Recording Co., 10-94.

-By Brent Kendall, Dow Jones Newswires; 202-862-9222; brent.kendall@dowjones.com