The fear of being sued by the record industry has led 38 per cent of music downloaders in the US – an estimated 6 million people – to stop downloading copyrighted music from the Internet, according to new research.

Lee Rainie, director of the Pew Internet & American Life Project, told The Washington Post: "The Recording Industry Association of America's (RIAA) decision to sue thousands of Americans who illegally traded and downloaded copyrighted music files had an immediate effect on file-sharing.

"Once the first formal legal challenges took place, the public's mindset shifted. There's a wariness that we never saw this time last year."

Yankee Group analyst Mike Goodman told The Boston Herald: "The lawsuits helped reduce music downloaders by at least 50 per cent, but millions are still downloading tunes without paying.

"They've driven out the casual downloader and they've driven out a lot of kids who were downloading because parents may not have been aware of what their kids were doing."

But the effects of the RIAA's campaign may be short-lived. The overall percentage of people who say they currently download music has inched back up since November – 18 per cent of Internet users say they now download music over the Internet, an increase from 14 per cent in a pre-Christmas survey.

Rainie noted: "The limits of the association's legal campaign are evident in the recent increase in active music downloaders. In general, it's not a great long-term business strategy to sue your customer base. There is a natural limit to how far even the aggressive legal tactics of the RIAA can reach."

The study does not distinguish between illegal downloads and songs bought through authorized sites such as iTunes.

Seventeen percent of the current downloaders did say they use paid services, though not necessarily exclusively. Reports Associated Press.