Earlier quoted context omitted.
If you mean the conspiracy theory, then some proof would be in order. That happening, and most people believing that to happen, are both outlandish claims. Spoiler: it actually does not happen. As the other person commented, snooping like this in scale would leak.
I don't understand this "argument from incredulity". It has leaked - you found out about it. Do you want them to publish an article in NY Times saying "yes, we spy on you all the time"? Do you want a personalized letter? What, exactly, is the form of this "leak" you expect would happen if this were true?
Edit: since you're asking, proof could be multiple testimonials from ex-engineers working on the project or a peer-reviewed article in a serious journal. Until that this is in the same bin with healing crystals and chemtrails.