This paper from Lawrence Livermore describes what can be seen just by looking at network flow data.

FORBES: Uncovering the unknown threat via beaconing detection

We built this network media flow where we were going to go around the cellular network and broadcast data to the device.

FORBES: Q&A: Qualcomm Chief Executive Paul Jacobs

In particular, the participants set out to identify researchers and other qualified personnel from different Andean countries, who could form the nucleus of a Working Group on Snow and Ice within the framework of an Andean-FRIEND (Andean - Flow Regimes from International Experimental and Network Data).

UNESCO: Valdivia, Chile, 2003