[educating]

> Just out of curiosity, how would we know even if a secret was let out to, say, the NSA

And the smartest thing to do, whether you are the NSA or some other foreign government or any entity that holds that information, is to keep quiet about it. The less others know that you know something, the more power you have.

For that reason, it is unlikely that we will see these powers used by the NSA, or other government. It is in their best interest to hold on to that data as secretly as possible and as restrictively as possible, to avoid the chance of others getting a hold of the data. Snowden if anything has only given the NSA and all others who hold the information that we do not know about reason to be careful open even mentioning that they have the data, to anyone.

[SideburnsOfDoom]

> For that reason, it is unlikely that we will see these powers used by the NSA, or other government.

The "parallel construction" mentioned above is how they do use these powers while obscuring the use of these secrets.