exmem registry

From my scant scanning and surfing of exmem websites there does not seem to be any registry or census taking of exmembers (I could be wrong). This wouldn't have to threaten anyone's privacy or anonymity; it's just an informal way of getting some very interesting numbers. I can think of countless uses for this too e.g. speedy communication of important news and helpful services, as a lobby group if/when we get to that point, easier reconnection with old friends, as a resource for sociology/psychology studies, etc. I know some may be wary and weary of groups but this is in no way a controlling type. Something like a subscription list or alumni association. I bet we'll all be surprised by the facts if and when we start this rolling. Any opinions?