Hacking from the Inside

We hear so often about governmental and/or industrial hacking against a government and/or industrial concern.  What we never hear about, very much, is hacking from the inside.  The "insider hacking" is behind the firewall, inside the layers of protection, and inside the detection screens.  The insider hacker knows the full protocols of the system and is accustomed to working within them.  It is still not the work of an amateur, but the location is closer to where the information is kept.

Suppose someone, rather gifted in this art, is compromised.  (Spies have been doing this forever.)  The price of silence is information.  The horrified victim dreads the revelations and agrees to comply.  Then, voila, information is extracted, and later transmitted, and used by the enemy - whomever.  No one ever knows.  This sort of hacking remains undetected for a long time.  Insider hacking has betrayed nuclear for generations, industrial secrets for centuries, and military secrets for millennia.  This is one thing that worries me about the massive modern databases held by agencies (of all flavors) we should trust.

In our current situation of "meta-data" reposited by the NSA, this type of hacking completely transcends the rigors of a court order.  In the private sector, the collection of any and all data is an obstacle that never was.

Please note: hacking can take many forms including misinformation about what is known, what could be known, and what will be known.  If my opponent believes I have something deleterious, it really doesn't matter if I have it.