Would foreign nation spys really install visible cell antennas?
Most IMSI catchers appear to be very compact devices, with a small range. Even an industrial scale one is smaller than a street lamp. So I'd guess for the most part yes they are visible, but so insignificant that nobody notices. And another reason not to hide is that foreign powers would be using a front company for it, with a long chain to obfuscate who is paying, and who is benefiting. I can't really see the PLA or FSB using liveried vans to put up a fake cell tower, complete with "Property of the People" plates on it.
Biting the hand that feeds IT
