Major record labels have been snooping onto the world's peer-to-peer song-sharing networks in a bid to measure which artists are proving popular among file-sharers.

Media tracking company BigChampagne has been monitoring P2P services since 2000, and has sold the data it collates to some of the industry's biggest names, the company claims in an AP report.

Garland's organisation measures how frequently clients' artists are listed in searches conducted on the P2P networks, including Kazaa and Altnet. It also tracks how often clients' songs are downloaded.

The company's actions have led to accusations that it is infringing P2P users' privacy - though how anyone illegally distributing copyright material can complain about that is hard to see.

BigChampagne denies the allegation. It also states that it hasn't helped the Recording Industry Ass. of America (RIAA) identify file-sharers for the purpose of suing them.

That hasn't stopped Altnet threatening to take legal action of its own. It alleges that BigChampagne's snooping system violates its own intellectual property. The irony of the allegation can't have been lost on any of the parties concerned.

BigChampagne's system appears to Kazaa or any other P2P network as a user, and is able to initiate searches for songs or other content. It can also track what's being downloaded. Garland told AP that the system doesn't record usernames. However, since it can collect IP addresses, it can be used to zero in on users' ISPs, and so could be used to co-ordinate action against file-sharers. ®