If they released all of them the aftermath would be as world changing as 9/11 itself, so to give the culprits the ability to delete everything will mean we'll never ever find out the truth. you will go down in history if you release them, that is worth far more than a material thing such as money.
RE: The Dark Overlord Hackers Begin Releasing 9/11 Documents - WTF is Going On?!?! Legit Hack? Psyop? Fake Truthers? - '9/11 Papers MegaLeak'