Once the encryption on the DVD's is broken, movie executives argue, people can copy and distribute movies at will without paying for them.

The film studios argued that Sony should be liable for copyright infringement since its video recorders could be used to copy movies and television programs illegally.

"The studios will not let us copy movies onto servers, and so we can't distribute them around the house," he said.

Digital Rights Management (DRM) is a way to make it impossible to copy music, movies, and computer programs.

Almost all of the 31 factories are believed to have illegally copied music or movies at some time.

At issue was the distribution of a code-breaking computer program that can be used to copy movies from digital versatile discs, or DVD's.

Piracy, these days, refers more often to digital miscreants who copy music and movies than to skull-and-crossbones derring-do on the high seas.

In the late 1970's, motion picture companies sued to stop the sale of VCR's, arguing that the industry lost money anytime viewers copied movies from television broadcasts.

Mr. Shamos said the practice of using DeCSS to copy movies is on the rise.

The ethical questions that arise from software piracy are : is it immoral or wrong to copy software, music, or movies?