The technicalities of the suit are a bit complicated: Young Money is an imprint of Cash Money, which is distributed by Universal. Wayne suggests that Universal is keeping profits from him, generated by artists that he discovered himself, including Nicki, Tyga, and Drake.
But it doesn't stop there: Wayne is also taking on SoundExchange, which collects and distributes royalties, saying that "Universal has claimed a right to 100% of the label performance royalties attributed to the YME [Young Money] Records" and "SoundExchange refuses to pay any of the money due to Young Money LLC and Carter individually based on Universal's conflicting demand."
This isn't the first of Wayne's legal battles. Just last year, Carter took on his patriarch, Birdman, over money generated from the forthcoming Tha Carter V album, creating a nasty feud between the self-proclaimed father-son duo. Although they were able to put aside their financial differences, Wayne continues to fight the Birdman-owned Cash Money label.
There doesn't seem to be too much precendent for this kind of lawsuit, especially in the rap world -- which makes it pretty hard to tell if Weezy is going for a nasty cash grab or if he actually deserves reimbursement for his curatorial talents. Either way: get that paper Mr. Carter! If you don't fight for your right to collect tens of millions of dollars for what might be dubious legal reasoning, no one's gunna do it for ya.