Don't conflate audio frequency, electromagnetic frequency, etc. in such a lazy, pseudoscientific way, please. The 440 Hz. A argument is historically absurd and scientifically nonsense. EM weapons aren't dangerous because of frequency alone. Sympathetic resonance frequencies have a perceptible and potentially destructive effect on homogeneous materials.
Do conspiracies exist? Yes. But correlation is not proof of causation, and observer bias readily finds associations where none in fact exists. Bad science used as a veneer of legitimacy for bad ideas is no friend of truth.