The Electronic Frontier Foundation (EFF) submitted its appeal this week following the January order issued by a Santa Clara County Superior Court judge in California.
The foundation argues that the Web site postings of the program are constitutionally protected free speech and do not meet the test of trade secret infringement.
"The battleground over the First Amendment is now in cyberspace," Jim Wheaton, senior counsel for nonprofit, public-interest law firm the First Amendment Project, said in a statement. "Old media is lumbering into the new era and wants to knock down our civil liberties in a clumsy attempt to maintain the old paradigm."
Wheaton is assisting the EFF in defending the collection of Web publishers named in the case.
A group representing the movie industry, called the DVD Copy Control Association, filed its lawsuit in late December after a 16-year-old Norwegian student posted on the Internet a program that defeats the security software on DVD-formatted movies.
His program, called DeCSS, allowed people to view digital movies through unauthorized players, such as computers running the Linux operating system.
The student was eventually charged by an Norwegian authority who seized several of his computers, a Nokia cellular phone and some CDs.
Nonetheless, the boy's program spread on the Internet like wildfire, leaving the movie industry frantically trying to stamp out the flames.
Lawsuits demanding removal of copyrighted material from the Web have become increasingly common as corporations seek to protect their intellectual property.
The entertainment industry in particular has struggled to keep consumers from making copies of its work.
But free speech advocates say that reverse engineering and the cracking of security codes constitute fair use of copyright-protected material.
"These cases are not about piracy or hacking," Tara Lemmy, the EFF's executive director, said in an earlier statement. "They are about censorship of speech critical to science, education and innovation."
A trial date for the Santa Clara County case has not been scheduled. A similar case filed in federal court in the Southern District of New York also resulted in a preliminary injunction against Web operators who were distributing the Norwegian boy's program.