[walrus01]

Things that transmit generally, in all sorts of bands, lots of countries where the government holds an armed monopoly on connections to the outside world.

Try setting up an independent two-way satellite based C or Ku band earth station in Ethiopia, offer service to your neighbours and armed men will come to dismantle it.

Commercial spectrum analysis tools are an essential and important things in the hands of network engineers, but also a tool to crack down on anything that transmits that an authoritarian regime doesn't like.