After what happened to MegaUpload and the lawsuits against Grooveshark, I'm a little afraid of making a username with Grooveshark. How private are they keeping that data in case the FBI or whoever storms their office? They should have a very tight policy for this to protect their users.
Unless you upload copyrighted music you don't have the rights to, you shouldn't be liable for anything even if the FBI or ICE does seize their servers.
It's light and fast. No flash annoyances. Also it doesn't have DPI issues.
Now then again, it's streaming MP3/AAC so only Chrome and IE seems to work ok.
Firefox for example just cannot play it.
Thanks patents.