> Maintaining a list of the top 1,000,000 bands in the world and not letting anybody upload tracks with metadata that included those bands and song names in it would not be that difficult.

I addressed this in my other comment, but as it turns out, this aspect of the problem is incredibly difficult. Metadata can be wrong and we can't always depend on it. So we use waveform analysis. But thats difficult too due to the indexing and storage requirements and the accuracy of the algorithm performing the search. Also this list is not finite. It changes constantly and parties are always bickering over rights to content and that takes time to sort out. We actually have a team of people who handle takedown requests, and we have another team of people who put in the necessary restrictions to keep content from getting played or uploaded.

The simple fact is, without mainstream content, Grooveshark would be a joke. Putting in a requirement - Do not play songs with the word Primus in the metadata - would probably "accidentally" keep out some cover bands' songs that are legally uploaded, but it would do a very good job of keeping out most Primus music. Even if that music showed up, but without the metadata, nobody would be finding it in searches, which also helps eliminate the use of that illegal content. What you do, frankly, is close to the legal minimum because the business wouldn't exist if you did a better job at it.

Within 5 minutes I can go find music on Grooveshark that is there illegally. It ought to be pretty easy for you to do the same queries and prevent that from happening. Would you prevent legal music? Yes. What is more important - that some cover band be allowed to post their music, or that Primus be allowed to retain their rights? Particularly when you consider that nobody is coming to Grooveshark to hear covers of Primus.

I'm not saying that operating legally in the music industry is easy - far from it. But on the spectrum of trying to, unprofitable Pandora is on one side, and Grooveshark is waving hello in the far distance.

If Primus sees their content on our site and they don't want it there, all they have to do is tell us. And we'll do exactly what you say by filtering any mention of the word Primus, take it down promptly and do everything we can to make it never happen again.

I see...so the bands are responsible for knowing about Grooveshark, policing Grooveshark, letting you know, and THEN you'll put preventative measures in place. The point is that those measures should have been in place from the get-go, because anyone in their right mind knows that Primus isn't sitting their uploading their tunes to Grooveshark.

P.S. I apologize for saying "the simple fact is" way too often.

Have you tried to do a fingerprint of files?

Also, what's waveform analysis?

It may not be legal. There is a "red flag" provision in the DMCA which could potentially make Grooveshark liable.

I remember Napster attempting to create a system to block subsequent "sharing" of known copyrighted works.