Nine Inch Nails frontman Trent Reznor has slammed his record label and strongly encouraged fans to steal music.

Reznor launched a stinging tirade against Universal Music Australia on Sunday at the group's concert at Sydney's Hordern Pavilion, dismayed at the high price the label charged for CDs.

He called the record label "greedy f**king assholes". It followed similar diatribes earlier in the year.

"Steal it. Steal away. Steal, steal and steal some more and give it to all your friends and keep on stealing," Reznor, who has been dubbed the Ralph Nader of the music industry, said.

"Because one way or another these mother f**kers will get it through their head that they're ripping people off and that's not right."

The group's latest album, Year Zero, sells for more than $A30 ($NZ35) in Australia, far more than albums from other artists.

A proud Reznor said Universal Music worldwide already hated him after he made similar comments on high CD prices the last time he visited Australia ("because I yelled at them and called them out for being greedy f**king assholes").

The Australian Recording Industry Association (ARIA), which has vigorously campaigned against music piracy, refused to comment on Reznor's attack. Universal Music Australia did not return calls requesting comment.

Reznor's endorsement of illegal downloading comes at a time when artists, particularly well-established ones, are cracking down on sites illegally distributing their music.

The crackdown is viewed by many as a desperate response to flagging physical CD sales in the face of digital downloads, both legal and illegal.

Figures released by ARIA last month revealed CD album and single sales dropped by 17 per cent and 47 per cent respectively in the first six months of this year, compared with the same period last year. Digital album sales increased by 67 per cent.

Last week, Prince said he planned to sue eBay, YouTube and The Pirate Bay for copyright infringement, in a bid to "reclaim his art on the internet".

Days later, Can't Stop Productions, which owns the rights to the Village People's music, said it was preparing to sue YouTube over a Hitler-themed clip that used the group's hit song, YMCA.

But Reznor, a self-confessed illegal downloader, has been campaigning to have CD prices reduced since May when, on the band's website, he noted Year Zero sold in Australia for $A34.99, compared with an Avril Lavigne album costing $A21.99.

He said a Universal Music rep told him the price was so high because Nine Inch Nails fans would buy the record regardless of its cost.

"No wonder people steal music," Reznor wrote.

This month before a concert at the Beijing Pop Festival he said: "It does not seem to be easy to obtain Western music via legal channels, so I have the following suggestion for our fans: if you can find and buy our legal CDs, I express my thanks for your support.

"If you cannot find it, I think that [illegally] downloading from the internet is a more acceptable option than buying pirated CDs."

Reznor told his Chinese fans that Nine Inch Nails would put out one last album for Universal, after which it would sell directly to fans through its website for as cheaply as $A4 an album.

- Sydney Morning Herald