The music industry is now testing different copy protection systems on mass market chart CDs, with copies of NSync's Celebrity on the Zomba label being sold in at least three different versions. Those available in Germany have draconian protection, a slightly weaker system is used on the US disk and there is no protection on the UK version. The only visible clue is small print on the German release which warns "this CD is not playable on computers". Sony will not comment on the NSync disc but a spokesman says: "We continue to test available copy protection technologies, and our goal is to implement copy protection on a broader basis to deter digital piracy." Sony presses the German disk at its DADC factory in Austria. Sony DADC also developed the key2audio system used to protect promotional copies of Michael Jackson's latest single. All three discs appear to play on consumer CD players, though Super Audio CD players from Philips and Sony took around 30 seconds to recognise the German version. Both the UK and US versions will play on a Windows PC and both let a PC CD burner make a copy onto a blank CD. But the German version does not even play on a Windows PC meaning users cannot listen to music they have bought, while they work. It cannot be copied to blank CD or sent over the internet using a PC. Nor can it be ripped to a solid state portable, such as an MP3 device. However, Apple Mac users have succeeded in playing the German disc.

Copying using home CD recorders is variable, with the US CD giving a "no disk" message on some recorders. When the digital output from a CD player is connected to the digital input of Philips CD recorder, or Sony Mini Disc recorder, the German disc gives the error message "Copy Prohibit" or "Cannot Copy". Although all CD copy protection systems can be defeated, with only slight quality loss, by connecting the analogue output of a CD player to the analogue input of a digital recorder or PC sound card, the convenience of automatic track indexing is forfeited..