There's much more we don't know, and often what we know is obsolete. We know quite a bit about the NSA's ECHELON program from a 2000 European investigation, and about the DHS's plans for Total Information Awareness from 2002, but much less about how these programs have evolved. We can make inferences about the NSA's Utah facility based on the theoretical amount of data from various sources, the cost of computation, and the power requirements from the facility, but those are rough guesses at best. For a lot of this, we're completely in the dark.
And that's wrong.
The U.S. government is on a secrecy binge. It overclassifies more information than ever. And we learn, again and again, that our government regularly classifies things not because they need to be secret, but because their release would be embarrassing.
Knowing how the government spies on us is important. Not only because so much of it is illegal -- or, to be as charitable as possible, based on novel interpretations of the law -- but because we have a right to know. Democracy requires an informed citizenry in order to function properly, and transparency and accountability are essential parts of that. That means knowing what our government is doing to us, in our name. That means knowing that the government is operating within the constraints of the law. Otherwise, we're living in a police state.
We need whistle-blowers.
Leaking information without getting caught is difficult. It's almost impossible to maintain privacy in the Internet Age. The WikiLeaks platform seems to have been secure -- Bradley Manning was caught not because of a technological flaw, but because someone he trusted betrayed him -- but the U.S. government seems to have successfully destroyed it as a platform. None of the spin-offs have risen to become viable yet. The New Yorker recently unveiled its Strongbox platform for leaking material, which is still new but looks good. This link contains the best advice on how to leak information to the press via phone, email, or the post office. The National Whistleblowers Center has a page on national-security whistle-blowers and their rights.