In a strange technological twist, it seems that music listening and song logging website last.fm may have turned over information logged by its scrobbling software to the RIAA. The situation in question concerns a leaked U2 album and users whose scrobbling software revealed them to have downloaded the leaked album, a clear violation of copyright laws.
The fine folks at TechCrunch have a full rundown of the situation here.
Update: Last.fm has responded:
Of course we work with the major labels and provide them with broad statistics, as we would with any other label, but we'd never personally identify our users to a third party - that goes against everything we stand for.