Sony once sued itself; RIAA (partially controlled by Sony Music) sued Launch.com (owned by Sony’s Tech & Business unit), meaning that the Music Dept. somehow sued it’s Tech Dept.
In NYC, you cannot sue the city for tripping on cracked sidewalks unless the city was previously aware of the cracks. As a result, lawyers pay people to map every single crack so they can sue the city more easily.
In 1994, a man walked into a Washington middle school and killed his former teacher. 11 years later, the killer won $250,000 from the school district after it was revealed that the teacher sexually abused him.
In 1978, Apple Corps, founded by The Beatles, sued Apple Computer for trademark infringement. Apple Corps won, and Apple Computer agreed to not enter the music business as part of the settlement.