How about Paramore, when Josh and Zac Farro left the band? Not exactly a break up, but, boy was it messy. They had a pact that they wouldn't do anything that went against the bible and Hayley Williams wrote a song with a lyric that did. They didn't like it be Atlantic Records forced them to record the song and release it as a single. Finally that had enough and quit. Then it was later said that Paramore wasn't exactly a band but Hayley's cheap backing band. Oddly enough Hayley and the other Paramore band member still use the Paramore name that was around before Hayley was ever in the band.