Heightening the tension surrounding the music industry's efforts to guard its content in the digital realm, the five major record labels have been hit with a class action lawsuit producing and distributing CDs with copyright protection controls.

The suit, filed in a Los Angeles court, names as plaintiffs two California residents who purchased CDs that they claim were "defective".

In an effort to safeguard their copyright-protected works, the major music labels have recently begun distributing CDs with controls that prevent them from being copied or played on various consumer electronic devices such as personal computers, CD players and car stereos.

The suit, which has been filed against Universal Music Group, EMI Music Publishing, BMG Entertainment, Sony Music Entertainment and Warner Music Group, represents one of consumers' first legal challenges to the music industry's efforts to clamp down on piracy by employing technological controls.

The lawsuit alleges that the defendants "manufacture, disseminate, advertise and sell defective audio discs". Furthermore, it rails against the labels' practice of not informing consumers in many cases that the discs they have purchased include copy protection.

The music industry has said, however, that music creators have the right to protect their works from piracy and have done so for years without it being deemed unlawful. Furthermore, they point to the fact that only a handful of CDs have been distributed with the protections included so far.

Asked about the possibility of a similar case being brought here, UK lawyer Alex Chapman, from Briffa, a practice specialising in technology and intellectual property, told us the law surrounding such allegations is trickier in this country.

Chapman says that under the Copyright, Designs and Patents Act, users have a right to make backup copies of CDs, however he said that the decision as to whether adding software that prevents this actually circumvents this act would have to be decided by the courts.

As far as consumer law is concerned, UK customers would only have the right to challenge record companies if they failed to state on the packaging that such copyright protection was present on the CD. If this were the case it may be possible to argue that the CD was not of satisfactory quality, says Chapman.