When you are acquired for $2 billion, know that there will be hundreds of lawyers looking to find a way to sue you and get some of that Facebook stock.
I think it's worth pointing out that ZeniMax has been pursuing this since 2012, long before the Facebook acquisition. At least according to this article on ArsTechnica:
it might be true that they were pursuing it earlier, however, according to the WSJ article that is the source for all this, the lawyers didn't get involved until after the Facebook announcement.
The letters from ZeniMax's lawyers came after Facebook struck its deal to acquire Oculus, part of the company's efforts to leap from a social-media platform to a major player in the race with Google Inc., Apple Inc. and Amazon.com Inc. to be at the forefront of Internet use.
