1 exception doesn't disprove this rule. There could be any number of reasons for one or some civilisations to broadcast but not be destroyed: * it takes time,

1 exception doesn't disprove this rule. There could be any number of reasons for one or some civilisations to broadcast but not be destroyed: * it takes time, we've only been broadcasting for 70 years or so. 70 light years isn't that far. * we are far from dangerous listeners (we are right out on an arm in the milky way galaxy) * all planets broadcast for a while at least (we did so without any serious consideration) and not all broadcasts end in annihilation. Up until just 40 years ago we seemed pretty likely to wipe ourselves out with war, even if an alien were planning our destruction, why not wait and see if we did it ourselves? * Popular methods of destruction might not apply to our solar systems. If you rely on near by asteroids or free-floating planets to destroy civilisations and there happen to be none near sol, then we are safe to broadcast even if no one is safe to reply. * if more than 1 alien actively destroys planets we might be lucky and have the aliens who detected us assume other aliens will destroy us. As long as they are happy to wait, we can broadcast in blissful ignorance believing we disproved the dark forest when we're actually just in the middle of a Mexican standoff... * If a civilisation destroys other civilisations as soon as it detects them, you can use the abrupt destruction of civilisations to triangulate that civilisation. And destroy it. And that's a high priority since that way you find hidden civs AND ones which pose an immediate and serious threat to you. The best defence against this is to allow plenty of time between detecting and destroying a civilisation, especially a harmless unarmed (in the cosmic scale) one like ours. The lack of many close neighbours to us means a would be destroyer needs to wait even longer before striking us to maintain their annonimity. Ironically this last point is the best argument against the dark forest: why destroy soft targets like earth when doing so reveals your existence? Why not wait, let someone else hit us and then hit them since they were a much bigger threat. So you'd expect a certain amount of noisy "prey" to be left as bait by one predator for another... Also, I don't think we are broadcasting very much anymore. The move to digital broadcasts (lower power) and to Internet based comms/media (99% undetectable even from orbit) mean we're a lot less visible than we were previously.