USA Today reports that a congressional bill could threaten music-player makers such as Apple.

The Inducing Infringement of Copyrights Act aims to make operators of networks such as Kazaa and Grokster liable for their users’ copyright abuse, and also makes it easier for entertainment companies to sue technology firms in language "so broad it could apply to makers of MP3 players, such as iPods."

It could also theoretically be applied against media organizations that give consumers tips on using digital content, the report warns.

Google, Yahoo, Intel, eBay, Cnet and 37 other firms have signed a letter requesting hearings on this issue, as in the US such bills can pass into law without any hearing at all.

"The act could be used to challenge free speech, which would violate the First Amendment and is a significant concern to us as a media company," says Sharon LeDuy, general counsel of Cnet.

"We feel this bill adds potential liability to any innovator," says Don Whiteside of Intel's Corporate Technology Group. "We view this as a very significant change in the copyright law, and we're very concerned."