> If the NSA was owning everything in sight (and by all accounts they have) then how is it that nobody ever spotted them
I think this should rather say "nobody ever came forward". I'm sure there always were enough pieces of evidence even if scattered and nobody had the whole picture. But the ones who were close enough to put together some of it and get an idea had no incentive to open their mouths.
Coming forward with enough evidence was likely close to impossible until a decade or two ago. The ones who have such comprehensive evidence also have some "incentive" to keep quiet. Up to the proverbial "terminated with extreme prejudice" option, which I'm sure must have been employed given the sensitivity of the topic. Or perhaps risking being labelled a terrorist which would likely lead to even worse outcomes. When the efforts were escalated after 9/11 so were the security measures and the "incentives".
And coming forward with just shreds of evidence of something like this will only get you labelled a nut, enemy of the state, shill, etc.
Snowden and a few others did it at great personal cost and I'm sure they now serve as an example for others to not do it. Look around even today, people see the world in black and white and if you're not with them, you're against them, and they will treat you as such.