Consumers should be told exactly what they can and cannot do with songs and films they buy online, says an influential group of MPs in the UK.
Portable music players are proving enormously popular
The All Party Parliamentary Internet Group looked at how copy protection systems restrict the way digital movies and music can be enjoyed.
Labels on digital content should spell out how easy it is to move from gadget to gadget, said the report.
It also called for an inquiry into the pricing schemes of online music stores.
A public inquiry organised by the MPs sought views on copy protection technologies, known as Digital Rights Management (DRM), from industry groups, consumers and media makers earlier this year.
DRM systems are becoming increasingly popular as the makers of music and movies, as well as operators of online stores, try to limit piracy of copyrighted works through home computers.
DRM systems can include special formats for media files or proprietary media players.
Apple's iTunes store prompted huge growth in downloaded music
For instance, a DRM system may allow a CD to be played on a PC but would not let tracks from that album be copied so they can be listened to on a portable player such as an iPod.
The MPs' report made several recommendations and called on the Office of Fair Trading hasten the introduction of labelling regulations that would let people know what they can do with music and movies they buy online or offline.
This would ensure that it was "crystal clear" to consumers what freedom they have to use the content they are purchasing and what would happen if they do something outlawed by the protection system.
The same labelling systems would also spell out what happened in the event of a maker of DRM technology going bust, if a protection system became obsolete or if gadgets to play the content are replaced.
Lock and load
The report also called for the makers of DRM systems to be made aware of the consequences of using aggressive copy protection systems.
This recommendation was made because, as the report was being drawn up, information was emerging about the controversial copy protection system employed in the US by Sony BMG.
This system used virus-like techniques to hide itself and stop CDs being copied. The row over the software ended up in the US courts.
Firms employing DRM systems needed to be aware that using such systems in the UK would mean they "run a significant risk of being prosecuted for criminal actions".
The MPs called on the Department of Trade and Industry to look into the prices charged for the same digital content, such as music tracks, in different countries.
For instance some nations, such as the UK, pay significantly more for songs from Apple's iTunes store than customers in the US or mainland Europe.
"This is somewhat at odds with the notion of the 'single market'", noted the report.
A spokesman for All Party Parliamentary Internet Group said he expected a response from makers of digital content and hoped that the report would inform wider government thinking about copy protection.
In particular, he said, it would provide input for the ongoing Gowers report into intellectual property.
Suw Charman, executive director of the Open Rights Group which campaigns on digital rights issues, said the organisation was pleased that the MPs had made a series of "sensible recommendations".
Consumers are bumping up against copy protection systems
But, she added, the group could have gone further to combat the ways that copy protection systems impinge on rights to use copyrighted material protected by law.
For instance, she said, UK law allows people to make copies of parts of copyrighted works for the purposes of critiquing or reviewing them.
"That's an exemption thwarted by DRM systems," she said. "The technologies are extending beyond the law they are supposed to uphold."
Increasingly, said Ms Charman, consumers were bumping up against DRM technologies as they use digital media such as downloaded songs.
She said that DRM was less about protecting copyright and more about creating a system in which people rent rather than own the media they spend money on.
"We think people rightly feel that once they buy something, it stays bought," she said.