The anti-copying technology uses deliberate errors in the CDs which are supposedly inaudible to humans but which will stop the CDs playing on computers – thereby preventing the ripping of the CDs for distribution in electronic format over song-swapping services. A side-effect of the technology is that the CDs cannot be played in some CD players, not just computers.
According to Reuters, Philips, which controls the Compact Disc trade mark, is demanding that the record labels warn consumers with notices on packaging that what they are about to buy is "not a compact disc, but something different." Philips would also bar these labels from using the Compact Disc trade mark.