Palantir is not a tentacle of the NSA. Not even close.
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.