How is the SEC responsible because they got hacked? Are you responsible for fraudulent charges on your credit card (you'll contrive some yes, but the answer is no)?
Certainly you will admit at some size, responsibility and level of funding the organization should take responsibility for protecting itself from hacks. If the Department of Defense got hacked and nuclear secrets were leaked, I certainly hope people would get fired rather than sympathized with.
The DOD doesn't use Twitter, a social media platform, as the mechanism for launching nukes... what are you talking about?