This bit from the heise.de article stood out:

Kiteworks, on the other hand, is less than enthusiastic about – a closed group of developers who are now using the same code in their own company that they already developed under Kiteworks or ownCloud? For Kiteworks, this smells like poaching, so the company is going on the offensive: in an interview with heise online, Kiteworks CEO Jonathan Yaron stated that he intends to sue Peer Heinlein under German and US law: "We love open source, but we won't let anyone steal from us".

facepalm