Grooveshark possesses the greatest and best library of any music streaming service. This statement could be easily made with greater than a hint of sarcasm; not like licensed providers Spotify, Rdio, and Mog, Grooveshark is run on shaky legal ground, dancing round the blurry edges of the DMCA. Universal continues to be trying to sue the pants off of the service for a while now, but it has now been joined up with in the lawsuit by fellow labels Sony and Warner Music Group.

Grooveshark’s unspoken strategy has been to acquire popularity through unlicensed content, and after that use that to purchase its way into legitimacy. The approach indicates signs of working, as the company signed a deal with EMI in 2009. General, nevertheless, released a copyright infringement lawsuit in early 2010, and the other last month. The more recent lawsuit is requesting $150,000 per alleged infringement $17 billion total from Grooveshark; this is the suit that the some other labels have piled onto.

The reason why the sudden piling on? Music streaming services is growing in popularity this year, and the labels need to make sure customers only choices are the ones that are paying up. However the biggest reason for the suit surge relates to alleged leaked emails. They allegedly document Grooveshark employees uploading music themselves and deliberately taking their old sweet time with DMCA takedown requests. The labels usually have hated Grooveshark, but now they think their case against them is stronger.

Will certainly this be the end of our preferred quasi-legal subscription service? Certainly not. There are parallels to Viacom’s 2007 lawsuit in opposition to YouTube, which was finally thrown out. That judge dominated that Google’s service was protected by the safe harbor provision of the DMCA. This enables services like YouTube to host potentially-infringing content, provided that the company responds to copyright holders takedown requests. Grooveshark’s greatest problem may be the alleged email leaks: evidence of a company deliberately flipping the bird to copyright holders could spell trouble.

Regardless of end result, the legal battles aren’t more likely to end anytime soon. Grooveshark is nevertheless here, and can still be here months from now. If you’re a customer, enjoy; just don’t be surprised if you have to get a new service a year or two from right now.