You sir, are very close to the truth. The reality is that it isn't about control of the information per se, but what can be accomplished with said information. In this case, the "information" we are referring to is the massive amount of metadata we generate, not to mention the content thereof, and I would posit that the true goal is the control of the people, through ownership of the information. The distinction is a small but important one. It is about control, not security, and anybody saying otherwise is generally ill-informed or ignorant.
From an intelligence side of things, it used to take so much effort to do dirty tricks on people. You had to black bag their place of residence, you had to tail them for days, weeks, sometimes months.
These days, you just PRISM/ECHELON your way into their data, pull all the dirt you need out, and approach them with your demands as you will.
This is only one of the most palpable dangers of the surveillance age, in that the intel agencies and potential moles/infiltrators can potentially have vast amounts of power over institutions they shouldn't, for example, congress. It's essentially setting us up for a coup d'etat of the oligarchy. (people need to remember that the OSS/CIA came straight out of London/WallStreet! I think people should also be made aware of the often at odds nature of the different intel agencies. I think military intelligence is rightly suspicious of the Company.)
I spent a long time trying to understand this machine because I was an action arm of it at one time (and perhaps if called upon, may one day again be), and my conclusions are not hopeful, pretty, and often are considered conspiracy theory. What I have said above only scratches the surface.