haha, what? Grooveshark profit off streaming content they do not have the rights to stream and abuse the DMCA to get away with it. As much as the music industry is broken and as awesome as the DMCA is, Grooveshark is not in any way shape or form an example of its true (or proper) purpose.
Grooveshark suck, they wilfully let users upload pirated material (if they didn't want it to happen they could easily prevent it, how many labels just mosey along and upload an artists entire library to a service without as much as a phone call?) and then use the DMCA to justify it, "oh if you don't want it here you can remove it!". No thanks, not supporting them, if they want to be legit they can follow Spotify in their methods.
Edit: I'll find the grooveshark AMA from reddit where a bunch of employees basically said "we don't know how we get away with it, that's for the lawyers".
Edit: Here you go, here's the IAMA: http://www.reddit.com/r/IAmA/comments/c2udg/iama_grooveshark... and a comment from an artist http://www.reddit.com/r/IAmA/comments/c2udg/iama_grooveshark... who happens to want his music there, but what if he hadn't? They have made money off it until he noticed, how on earth is that justifiable? Why didn't they do what Spotify did? Maybe that's the sort of thing ycombinator likes, just saying "whatever fuck you" to an industry that works differently to how you'd like, but doesn't seem ethical to me...
"As many of you know, we are involved in a major lawsuit with Universal Music over this exact issue." because you took their content and made money from it without permission. "We’ve worked hard to stay legal so that we can continue bringing you the music you love, and a few minutes of your time could go a long way." we've worked hard to abuse the rights we have to make money from stuff we really shouldn't be without permission. If someone came along and made a website (think themeforest) and took your website designs and sold them until you said "oh hey, uh, can you stop selling my work?" would you support that? So much contempt for the music industry makes easy for grooveshark to persuade people to support them, when if it were an industry people using grooveshark worked in they'd be super pissed.