The website MySpace.com has unveiled a copyright crackdown.

The News Corp operation said it has licensed a new technology to stop users from posting unauthorised copyrighted music on the social networking website and oust frequent violators of its policy.

The move comes amid pressure from major studios and record labels against popular online sites like MySpace and YouTube, which they accuse of infringing the copyrights of their artists' music and videos.

MySpace, one of the most popular sites on the internet, licensed technology from privately-held Gracenote allowing it to review music recordings uploaded by community members to their profiles.

The technology compares those filed with Gracenote's database of copyrighted material and can block uploads without proper rights.

Terms of the licensing agreement were not disclosed.

Among the stars to emerge from the MySpace is pop phenomenon Lily Allen, who came to public attention when she showcased her own music on the site.

Popular sites like MySpace and YouTube are littered with copyrighted music and video posted by their legions of users, who hope to share them with friends and strangers alike.

Both say they remove unauthorised copyrighted material when notified.

But MySpace, increasingly seen as a destination to see and hear music and video, will soon begin selling songs from nearly 3 million unsigned bands.

It aims to eventually offer copyright-protected songs from major record companies.

Once Gracenote's technology is integrated into its service, users who repeatedly try to upload unauthorised music will have their accounts deleted, MySpace said.

YouTube, which recently agreed to be acquired by Google, has similar aspirations to cash in on Web video use and protect itself from legal challenges.