Eminem cracks down on ringtones, karaoke

Eminem has filed a lawsuit against companies who sell ringtones based on his songs.

The lawsuit filed a US District Court in Detroit by the rapper's production companies seeks to prevent five companies from selling unauthorised ringtones of his songs online.

He is also keen to put a stop to karaoke companies who make money from his songs without a licence.

A legal spokesperson for Eminem is quoted by MTV News as saying: "This is a big business. We're talking hundreds of thousands of dollars a year."