That's what control means, the ability to alter your behavior or the course of events.When it became public knowledge that the US government had backdoors in the long distance telephone network, that did alter people's behavior and the course of events. Similarly, the public knowledge that the NSA is spying on the Internet is altering people's behavior and the course of events.
I agree the NSA can't stop people from visiting HN, but they can certainly change the incentives faced by people using the Internet. Perhaps this doesn't meet your definition of the word "control", but you still seem to find it significant.
this is not historical fact
What isn't? Are you saying that you don't believe the US government put backdoors into the long distance telephone network? Or that you don't believe the NSA is spying on the Internet? Or are you just saying you don't care, because you can still visit HN? That doesn't change the historical fact; it just means you don't care about that particular historical fact.