The Electronic Frontier Foundation (EFF) is deeply critical of all existing digital rights management (DRM) systems.

In a non-partisan report, it slammed all available services for their systems, saying they all: "Compromise a consumer's right to lawfully manage her music the way she wants".

The EFF has published a report - "The Customer Is Always Wrong: A User's Guide to DRM in Online Music".

"Although these companies claim their services allow consumers "freedom" and the ability to play music "any way you want it," the reality often does not live up to the marketing hype. When you download in these formats from online music services, the services don't trumpet the fact that your music contains hidden restrictions that complicate your life and limit the universe of devices you can use to play your music."

Apple, Microsoft, Real, Napster all come in for a pasting: Apple for locking users into its digital music experience, and Microsoft for failing to ensure members of its 'Plays for sure' programme actually meet the mantra.

The report takes a close look at each service, contrasting the usage rights of these services with those available to CD buyers.

"In this brave new world of 'authorized music services', law-abiding music fans often get less for their money than they did in the old world of CDs', the report declares.