I have a friend that works for a chip company and he said he couldn’t get into details but the amount of back doors in communication companies and in chips would scare the shit out of me.
I say this because NSA seems more clever than that, and because any scheme to explicitly add back doors is bound to be eventually exposed.
Instead they do things like have their former employees and contractors hired into tech companies, and those folks add innocuous bugs that can plausibly be denied as back doors. Also I bet they look for bugs that can be used as back doors, given access to source code and chip design data, then fail to fix them.
Most if not all ICs above a certain intelligence level have JTAG, which effectively is a backdoor. All you now need is (for those chips that support it, in the first place...) a way to bypass the OTP fuses "preventing" JTAG access - this kind of vulnerability turns out often enough to be saying it's commonplace.
Neither of these anecdotes proves anything.
We had one anecdote saying a thing is happening, the second from someone who says it isn't. Your post seemed to indicate that the second post isn't true because maybe that person just doesn't know about it.
That seems to refute the second and assume the first is true.