"If they keep discovered vulns to themselves"
.. they can get hacked, and black hats can get their mitts on juicy zero-days that they can exploit quickly because the spooks will have a devil of a time admitting that they sat on those problems instead of protecting the public - which is their official duty and gives them all their powers.
One day, I would like a Game-Of-Thrones ruler to turn on them and say "You knew this and kept it to yourself ?" - and then a public beheading.
As a lesson to the rest of them.
Never going to happen, because National Security is more important than your security as a member of that Nation.
Biting the hand that feeds IT
