In the wake of the recent NSA revelations, theres increased talk about the need to balance freedom against security. I even see people recycling Larry Nivens law that freedom + security = a constant.

Nonsense. What we want is not to be attacked or coercively interfered with  by anyone, be they our own government, other nations governments, or private actors. Would you call that freedom? or would you call it security?

You cant trade off freedom against security because theyre exactly the same thing.