That's the cool thing! No one really knows, so any remotely scientific theory is indistinguishable from truth. Maybe even the more outlandish the better, so as to scare people more effectively.

"...the importance of the energy being pulsed in order to have biological effects on humans. When you produce pulses like this, you can actually stimulate electrically active tissue like brain tissue and the heart, for that matter, mimicking what the brain normally does, but now you're driving it with your pulses from the outside."

Ah, so a portable pulsed microwave device. Current phased array technology is certain to be able to produce a narrow and powerful beam. Current energy densities of batteries allow for a significant amount of portable power. Expecting to see "Show HN" on this soon...