This seems like a freewheeling legal department trying to do its job, however poorly, with less-than-optimal oversight or communication with PR. That said I'm purely taking a stab in the dark without more details from the documents you were sent.
I seem to recall another story crossing HN over the last year with the general plot of "BigCorp is suing us for [ridiculously unrelated reason] when we have nothing to do with it!" before the bad PR hits and BigCorp issues a statement saying "Sorry. It's all cool, we didn't really mean to target you. In fact we even like you." If I can find it I will edit my post with the details.
I'm afraid it's generally far worse than a freewheeling legal department. But rather a bloated law firm retained to indiscriminately "defend" the FB brand, and whose daily mission it is to continuously justify monthly billables that would dwarf most annual software developer salaries (and then some).
I seem to recall another story crossing HN over the last year with the general plot of "BigCorp is suing us for [ridiculously unrelated reason] when we have nothing to do with it!" before the bad PR hits and BigCorp issues a statement saying "Sorry. It's all cool, we didn't really mean to target you. In fact we even like you." If I can find it I will edit my post with the details.