Bug /Spy / Listening Device 101 (Takes a spy to find a spy) Back when I worked for the US Intelligence Services (OGA & NGA), I learned the dynamics of covert and overt signal interception and countermeasures. We learned TEMPEST: EmissionProtection controls to ensure that foreign and domestic adversaries could not "intercept our communications that were "classified " As time progressed, I was taught the art of Humint / Sigint (Human and Signal) and All Source signal harvesting, collection, and ma