A judge has ordered Web site operators to stop disseminating a program that makes it easy to copy DVD movies and audio discs.
The software, called DeCSS, allows users to unlock the security code on DVDs and copy movies to personal computers.
A DVD trade group sued the Web site operators, alleging theft of trade secrets.
Santa Clara County Superior Court Judge William Elfving issued a preliminary injunction Friday barring the sites from offering DeCSS to users. His ruling follows a similar decision Thursday by a federal judge in New York, who ruled that three Web sites posting DeCSS had violated the 1998 Digital Millennium Copyright Act.
Lawyers for the site operators said the ruling was an affront to their belief in open sharing of technology.
"This isn't about hacking or privacy. It's about sharing legitimate information and code developed in the open-source community," said Tom McGuire, a spokesman for the San Francisco-based Electronic Frontier Foundation.