just a thought or two.
Funny how people always know the Best Solution after Murphy has struck..
That said, something on this scale is pretty much unprecedented, it's a whole level up compared to the usual leaks/breaches. Almost an Ocean's [umpteen] job compared to your run-of-the-mill bank robbery. Certainly not the work of your average script kiddie, or even dedicated lulzcrew.
One of the funniest things I see in the comments is that people assume they pulled all the data at once.. This Is Stupid... If the attack was as sophisticated as it seems to be, the people behind it could easily have slowly bled the data out without triggering any alarms. Comprehensive breach with elevated rights and stuff, you can, y'know..., do things, at leisure, under the radar...
Leaking the data to the Wide Intarwebs is also a brilliant idea to confuse the trail. Whoever did this is obviously fully aware of the lulzcrowd and their habits, and the lovely smokescreen it can provide. Given the scale of this, a smart person would stay the hell away from stuff this hot, but script kiddies and bragging rights, eh? Good way to create several layers of subterfuge and misdirection as to who has really done It. And most beautiful of all: the suckers do it to themselves, of their own free will, without having to prod them into action.
Nation state or criminal group ( and unless people have been living under a rock, yes, there are a couple out there that are just as sophisticated as quite a few Intelligence Agencies...) , this has been a big one, and the current broohaha is only the first chapter in the book.