The interesting thing about this lawsuit is that it is charging Amazon with various forms of trespass and breach of contract. One of the causes of action is for illegal hacking; one is for trespassing on the Kindle; one is for stealing the book; two are for breach of contract; and one is for deceptive trade practices.
The case has nothing really to do with copyright. It seems unlikely that Amazon can justify its actions on the grounds of protecting someone else's copyright. (If you sell illegal contraband to someone, you don't magically get a right to steal it back.)
If the case succeeds, it might have some interesting limiting effects on DRM systems.
So if this case succeeds, it might have