Are You Pondering What I'm Pondering?

A couple days ago NPR had a story on 411-Song, a service where you play a music clip into your cell phone and it texts you the song name and artist back to you. They claim to have a database of music larger than Napster and iTunes combined.

So my question is: Did they get permission from the various record labels to index their songs? It’s entirely possible they have, which may explain their low profit margins, but my guess is that they didn’t. And if they didn’t ask for permission, why hasn’t the RIAA sued them for violating copyright? The process of creating the index must involve making a copy of the music.

Now, I’m not suggesting that the RIAA should sue them. IANAL, but it seems like fair use to me. However, that’s the same argument that some publishers are making against Google Book Search.