A federal appeals court late Friday upheld the music industry's $22,500 judgment against a Chicago mother caught illegally distributing songs over the Internet.

The court rejected her defense that she was innocently sampling music to find songs she might buy later and compared her downloading and distributing the songs to shoplifting.

The decision against Cecilia Gonzalez, 29, represents one of the earliest appeals court victories by the music industry in copyright lawsuits it has filed against thousands of computer users. The three-judge panel of the U.S. Court of Appeals for the Seventh Circuit in Chicago threw out Gonzalez's arguments that her Internet activities were permitted under U.S. copyright laws.

Gonzalez had rejected a proposed settlement from music companies of about $3,500. A federal judge later filed a summary judgment against her and ordered her to pay $750 for each of 30 songs she was accused of illegally distributing over the Internet.

Gonzalez, a mother of five, contended she had downloaded songs to determine what she liked enough to buy at retail. She said she and her husband regularly buy music CDs and own more than 250.

However, the appeals panel said Gonzalez never deleted songs off her computer she decided not to buy, and judges said she could have been liable for more than 1,000 songs found on her computer.

"A copy downloaded, played, and retained on one's hard drive for future use is a direct substitute for a purchased copy," the judges wrote. They said her defense that she downloaded fewer songs than many other computer users "is no more relevant than a thief's contention that he shoplifted only 30 compact discs, planning to listen to them at home and pay later."

Gonzalez could not be reached for comment. Her lawyer, Geoff Baker, said comparing Gonzalez to a shoplifter was "inflammatory" but declined to comment further until he had more time to review the decision, which was released late in the day.

Gonzalez was named in the first wave of civil lawsuits filed by record companies and their trade organization, the Recording Industry Association of America, in September 2003.

"The law here is quite clear," said Jonathan Lamy, a senior vice president for the Washington-based RIAA. "Our goal with all these anti-piracy efforts is to protect the ability of the music industry to invest in the bands of tomorrow and give legal online services a chance to flourish."