Another day, another major label legal challenge… Elio Leoni-Sceti’s EMI has filed a lawsuit against Florida-based music streaming site Grooveshark, as AllThingsD reports. The site currently offers tracks from all four majors and has escaped the attention of their lawyers, until the suit was filed in New York in May. Earlier this year the label launched legal battles against music search sites Sideload and Seeqpod.

The site says in a statement: “For the past year Grooveshark has been in talks with EMI Records and other copyright holders to negotiate licensing agreements”—but then EMI “chose to abandon the template we’ve built… and opted for their traditional intimidation tactic of filing a lawsuit as a negotiating tool”. Grooveshark claims to have copyright deals with artists, labels and publishers (though it doesn’t name any) and warns EMI that it can either support legal music sites or “force customers to illegal networks”.

Whilst licensing services like Last.fm, Spotify and YouTube, EMI is not shy to go to court against startups: from its $100 million claim against Napster (NSDQ: NAPS) to its 2007 attempt to takedown MP3Tunes, which caused bizarre scenes at this year’s MidemNet, it likes to remind the world who owns its content. But legal action doesn’t necessarily mean deals can’t be done: Grooveshark may be hoping it can emulate US music social network Playnet which in March signed a content deal with EMI after the label had earlier joined a (still on-going) shut-down suit with other majors.

• Project Playlist Adds EMI Music But No Facebook, MySpace; Still Being Sued
• @ MidemNet: MP3.com’s Robertson Vs EMI’s Nicoli: A Legal Divide; Music Biz Failed Like Wall Street
• XM Settles Suit With EMI on Portable Music Player; Major Labels Out Of The Way
• EMI Suing More Music Sites For Offering ‘Playable Search’