This struck me as odd as well. I'm curious whether Rockefeller or someone close to him has been Whispering info they shouldn't have or would be embarrassed by. I haven't cared enough to look at the data stream between Whisper and its servers, but does anyone know if they send the GPS tag of each Whisper down to the app? You could build your own database this way. Even if they don't, with their "nearby" feature, you could make posts with fake locations and then look at what order they come up in the "nearby" results at different locations. You could then calculate a relatively precise fake GPS location necessary to feed to the nearby feature to pinpoint Whispers from a specific location.