It's pretty much an unsaid rule in the music industry that the songs written for each artist should be original work. Even if the singers themselves actually write their own music, it just goes without saying that they shouldn't be copying or stealing sounds, lyrics, beats – ANYTHING – that has already be done!

But, sometimes without knowing it they may get caught up in lawsuit that claims they copied someone else's work, regardless of whether they actually did or not! And that's when the drama REALLY starts.

From Justin Bieber to Alicia Keys we've found the craziest cases of stars being sued over their own songs!

Click through the gallery and let us know which case shocks you the most!