Even our multi-megawatt transmitters being detectable for tens of light years is largely a myth. Omnidirectional broadcasts need to be powerful just to be detec

Even our multi-megawatt transmitters being detectable for tens of light years is largely a myth. Omnidirectional broadcasts need to be powerful just to be detected several miles away thanks to the inverse square law. Most powerful TV and radio transmitters won't be detectable too far outside the solar system. It takes a lot of power (or a highly directional antenna) to send a detectable signal detectable light years away. The only unintentional signals we generate are high power weather and military radar. Those are very tight beams that sweep the sky. Any interstellar eavesdropper would need to have the beam sweep over them to detect it. Even then it would be a transient signal with no guarantee of repetition since everything is it motion. It would be like us being a mile apart in the blackest of night and you swinging a laser pointer around. Even if I'm looking specifically for you and have a general idea where you are the odds are vanishingly small your laser pointer will happen to be visible to me. You'd have to be specifically pointing it at me to even have a hope of me seeing it.