>>9784038 pb
>>9784094 pb
Maybe it does more than just track you.
"The Thing consisted of a tiny capacitive membrane connected to a small quarter-wavelength antenna; it had no power supply or active electronic components. The device, a passive cavity resonator, became active only when a radio signal of the correct frequency was sent to the device from an external transmitter. This is referred to in NSA parlance as "illuminating" a passive device. Sound waves (from voices inside the ambassador's office) passed through the thin wood case, striking the membrane and causing it to vibrate. The movement of the membrane varied the capacitance "seen" by the antenna, which in turn modulated the radio waves that struck and were re-transmitted by the Thing. A receiver demodulated the signal so that sound picked up by the microphone could be heard, just as an ordinary radio receiver demodulates radio signals and outputs sound. "
https://en.wikipedia.org/wiki/The_Thing_(listening_device)
So, in 1945, the Soviets had an unpowered listening device that broadcasted conversations, triggered only by hitting it with the right radio frequency. Imagine what they might do with that technology today?