He’s gonna use it as a get-out-of-jail-free card. It’s a way to extort America, turn around to say, if you put me in jail, if you go after me — he’ll even say his children — I will have my loyal supporters who you do not know who [have] copies of information … again this is my conjecture, that I would take those documents, I will release them to Iran, to China, to North Korea, to Russia.

Source: Why did he steal the documents? Maggie Haberman’s book may hold the answer | Salon.com