Techcrunch got its knickers in a twist in January after it revealed that Last.fm had handed details of its user's preferences to the RIAA. Now it has claimed that IP addresses were also handed over so that the RIAA knows who you are and exactly what you are listening too.

For those in Europe we should explain that Last.fm is one of the largest and most appreciated music communities on the Internet. But it was bought by CBS Interactive back in 2007 and many felt that it would eventually turn on its users in favour of the music and entertainment business.

TechCrunch claims that if CBS supplied user data to the RIAA, and that the data could possibly be used in civil and criminal actions against those users. In otherwords if a file sharer denied that it had been nicking certain types of music, the RIAA could say “really, but you listen to this all the time” also we know that you downloaded it from Last.fm and pirated it from that source.

However as Torrentfreak points out everyone can easily edit metatags they can never really be certain that an individual was indeed in possession of the track, let alone that they shared it with others. There are plenty of better ways to track down copyright infringers and the RIAA is well aware of that. They are experts by now, Torrentfreak points out.

What is more likely the RIAA is interested in the business intelligence value of the data and that means that it can tailor sales to particular markets.

More here.