DeCSS is a software program that allows decryption of a CSS-encrypted movie and copying of the files to a hard disc (CSS stands for content scrambling system, and it’s used to protect the content of a DVD disc.) The DeCSS utility made online trading of DVD movies possible, although the interactive elements and outstanding audio/visual quality of DVD are compromised in the process. The program caused a major controversy when released in late 1999, with the movie industry fearing a massive wave of piracy was about to begin.