Thousands of commuters are guilty of it every day, as are some of the trendiest politicians who now boast of owning iPods.
A report to be published today by the Institute for Public Policy Research will warn that millions of British music lovers are breaking the law by copying their CD collections on to their iPods and MP3 players.
Most iPod users are unaware they are breaking the law
Unknown to many, the provisions of 300-year-old laws that still govern copyright in the UK have the effect of making it illegal to "burn" tracks from compact discs on to a computer or digital music player.
Even the chairman of the culture, media and sport select committee inquiry into digital copyright, the Conservative MP John Whittingdale, said that he and his children had contravened the legislation by copying tracks from their CD collections on to MP3 players.
He said: "My own view is that the current laws are unsatisfactory as it is difficult to say to consumers that this bit of the law matters and this bit doesn't matter. The music industry has said it has no intention of prosecuting anyone for transferring music they have bought on to their digital music players."
The Liberal Democrat MP Lembit Opik said he had also broken the law by putting music on to his home computer. He does not own an MP3 player. And the former Labour MP Oona King said she downloaded more than 200 songs from her CD collection on to her iPod.
advertisementAides of David Cameron, who has boasted regularly of his love of his iPod, said they did not know whether he downloaded music exclusively from the internet or supplemented it with his own CDs.
The authors of the report, Public Innovation: Intellectual Property in a Digital Age, claim that the law, which is being examined in a review ordered by Gordon Brown, should be changed to include a "private right to copy" that will protect the owners of digital media players and allow them to copy CDs and DVDs for personal use.
Kay Withers, a research fellow with the IPPR who co-authored the report, said: "It makes no sense to the public if they are being offered opportunities to listen and watch media with new technology but are not legally allowed to take advantage of them. The law is out of date and confusing, which creates sympathy for the piracy activities these laws are designed to defeat."
Under the legislation it is legal to download music on to a computer when it is bought from a website, but copying music from a CD, even one bought legally from a shop, infringes copyright as it is a "format shift".
Unknown to many, the 1709 Statue of Anne which came into law as the first Copyright Act in 1710 still governs the enforcement of copyright in the UK. It thus prevents copying an artistic work into a different format, such as a record on to a tape, or a CD on to a computer file.
Up until 1710, the area of copyright was somewhat murky and even William Shakespeare fell foul of the lack of rights in common law that authors had over their own work.
Research by the National Consumer Council has revealed that 55 per cent of people in the UK burn CDs on to their computers. They also found that 59 per cent of more than 2,000 adults surveyed were unaware that such activities were illegal.