When the Russians first started transmitting in 1976, they emitted an eleven hertz signal through the earth. This ELF wave was so powerful that it upset radio communications around the world, resulting in many nations lodging protest. The U. S. Air Force identified five different frequencies the Russians were emitting in a wild ELF cocktail. They never broadcast anything below eleven hertz, or anything that would be beneficial. They had more sinister things in mind.
ELF penetrates anything and everything.
Nothing stops or weakens them. At the right frequencies and durations, whole populations could be controlled by ELF, or even killed. Once the killing range of these frequencies is perfected, it could make nuclear bombs obsolete. It could kill almost immediately with powerful adverse frequencies. Whole populations could be killed indiscriminately from radio frequencies transmitted from the other side of the globe without damaging anything else.