If America's tech giants didn't 'participate knowingly' in the dragnet of electronic communication, how does the NSA get all of their data?
Applying Occam's Razor, the dreaded nemesis of CT'ers of every stripe, it seems a whole lot simpler to posit that the tech giants (Or enough of them, or enough subassemblies of them) are either lying or really did participate and simply refrained from asking too many questions at the time so they would be able to stick that "Knowingly" qualifier into their not-really-a-denial statement if they were ever caught out on it.