Nearly three quarters (73 percent) of Brits don't know whether they can copy CDs and DVDs to their PC, says Consumer Focus.
Research by the consumer-advocacy organisation revealed that only 17 percent knew it was breaking copyright law to rip a CD to a PC, while even less (15 percent) knew it was illegal to copy a CD to a digital music player, such as an iPod.
Furthermore, nearly two in five Brits with a digital music player admitted to copying their CDs to the device.
Only 15 percent of Brits know it's illegal to copy CDs to an iPod
Consumer Focus said copyright law was outdated, as it was written before digital music files were invented, and needs to be updated.
"The world has moved on and reform of copyright law is inevitable, but it's not going to update itself," said Consumer Focus international director Jill Johnstone.
"If the government wants consumers to respect copyright law they have to stop sitting on their hands and bring the law in line with the real world."
The organisation called for "fair use" exceptions that would ensure consumers that have purchased a CD would be within their rights to copy the album to other devices such as a PC or music player, provided it was for their own personal use.
Consumer Focus said 80 percent of consumers agreed that copyright law should be updated to cover digital music technology.