I've been using Grooveshark for a couple of years now and I didn't even know they were illegal (I figured they had deals with all of the record companies) until I saw info posted about it here on HN.
They aren't technically illegal, as they (in theory) comply with takedown requests. Now, if GS staff are uploading songs themselves, then the safe harbor provision of the DMCA doesn't apply and they're in a world of legal hurt. IIRC, Universal's claim that staff are uploading the songs comes from an anonymous posting on a message board, so I doubt that claim will hold up if that's all it's based on.
Yes, but that's what the safe harbor clause is for. If a user uploads something, the site owner is not liable provided they comply quickly with takedown requests. It's why YouTube can allow users to upload videos, and a similar principle is the reason 4chan is still in existence despite the hundreds of thousands of child porn pics that have been uploaded to it.
I've been using Grooveshark for a couple of years now and I didn't even know they were illegal (I figured they had deals with all of the record companies) until I saw info posted about it here on HN.