I know for a fact many NSA employees read and enjoy participating on HN.
There's a few Palantir[0] employees here too, Palantir being one of the many tentacles of the NSA. Infact any contractor who does work for the NSA can be found lurking moar on HackerNews. If you do enough digging around you will find them. Palantir being the more obvious example.
A document leaked to TechCrunch revealed that
Palantir's clients as of 2013 included at least
twelve groups within the U.S. government,
including the CIA, DHS, NSA, FBI, CDC
[0] https://en.wikipedia.org/wiki/Palantir_Technologies#cite_not...
Even in the case of companies owned in part by In-Q-Tel I guess the point is to make their technology available to the US goverment. Maybe 20 years ago the goverment would fund that with DARPA or something similar, but now there is an open technology market and I guess they should be investing to get their opinion heard on the direction they need the technologies to evolve.
You could argue that any company that actively works with the NSA to increase their coverage is a tentacle.