In the 50's or 60's the Soviets tried some passive listening devices that were basically reflectors hidden in walls. When they were hit with microwave radiatio

In the 50's or 60's the Soviets tried some passive listening devices that were basically reflectors hidden in walls. When they were hit with microwave radiation, the reflected beams could allow them to capture conversations. It's not out of the realm of possibility that Russian intelligence services have improved significantly on this concept in the last few decades. Or that they found a way to weaponize it.