Brain science is chemistry + physics + what still is a bit of magic, but the problem I have with your basic premise is high school geometry.
In round numbers, there are an estimated 65 to 90 billion neurons in the average human brain (fewer in mine). That's a lot, and they're all in a space about the size of a softball. On the face of it that seems impossible, but in the simplest digital terms that's only 11.25 GB, and I have 350 times that much storage space in one 4 TB hard drive. There is evidence to suggest that a neuron is more like a multi-level cell (MLC, the most common form of memory in flash disk drives), but still, that's a whole lot of something going on in a very small space.
And that's the thing. Even if we could scan the brain and detect not just visual activity, but the actual image being seen, the music being heard, the thoughts being thought, you can't do it from a distance; partly because it is a 3-D resolution problem, and partly because things are just too small and too close together. Separate from that, the electrical signals representing vision, hearing, taste, motor control, etc. are very different in coding and content, but nearly identical in the broad characteristics of amplitude and frequency spectrum. At a distance they are a jumbled mess, and that mess is masked by everything in your space. EEG signal levels are in the nanowatt to microwatt range. Your TV radiates thousands of times more energy than your brain, much of it at brainwave frequencies. So apart from having to resolve the extremely small angle of incidence between the visual and motor cortexes (?) from tens or hundreds of yards (or miles) away, you have to find one needle in a building full of needles.
Planting thoughts is even more difficult, as anyone who has looked into wireless charging has learned. Beaming enough energy at an individual wire to override a conducted current in that wire takes a huge amount of radiation. Doing it without affecting the wires next to it requires beamforming (focusing) not possible with today's antenna designs. The military has been working on this for a few decades, and the current technology, at one mile, can resolve something the size of a tank. Resolving a few neurons, or even a billion neurons, just plain cannot be done. If it could, the world would have instant migrain relief with zero side effects at the flip of a switch. Way too many billions of dollars to be made to keep that a secret.
I do not doubt for a moment that your concerns are causing stress that is very real, with all of the physiological and cognitive consequences that are well documented. But my guess is that you are wrapped up in a common statistics fallacy, so well known that it has its own Wikipedia page:
https://en.wikipedia.org/wiki/Correlation_does_not_imply_causation
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