Hackers shouldn't be prevented from publishing online a code that allows DVDs to be copied, a California state appeals court ruled Friday.

A panel of the state's Sixth Appelate District ruled that posting of the links is speech, and prohibiting the publication of the codes is a prior restraint on speech that offends the First Amendment.

"Although the social value of [the code] may be questionable, it is nonetheless pure speech," the court wrote.

The suit began in 1999 when the DVD Copy Control Association, a trade group, sued Andrew Bunner for posting links to the code on his Web site. The lower court hearing the case held that the information was a trade secret and that Bunner could not distribute it pending a trial. Bunner appealed that preliminary ruling.

The case is one of several that has sprung up since hackers authored a code that breaks the encryption on DVD movie discs known as "content scramble system," or CSS. The code used to break that encryption has since been called DeCSS.

The fear of movie studios and DVD manufacturers is that, once someone has DeCSS, he or she can decrypt movies and store them as files on a computer. Those files could then be transferred via a Napster-like peer-to-peer network, causing the same kind of copyright violations as the recording industry faced with Napster.

While the case decided Friday concerned whether CSS qualified as a trade secret under California law, the ruling could influence a federal appeals court facing another case involving the DeCSS code.

The 2nd U.S. Circuit Court of Appeals is reviewing whether the encryption-breaking information violates the Digital Millennium Copyright Act (DMCA). The DMCA prohibits the use of technologies designed to circumvent encryption.

The California case is DVDCCA v. Bunner (Santa Clara County Super. Ct. No. CV786804). The federal case is Universal City Studios, Inc. v. Corely (appealing 82 F. Supp. 2d 211 (S.D.N.Y. 2000)).