This already happens. When someone goes to your neighbors and asks around about you, your neighbors probably spill everything they know about you immediately. (If not immediately, a little story about an "ongoing investigation" should push them over the edge.) It's going to work the same way on the Internet. It's a little scary, but I prefer to think about the good applications rather than the bad applications. Having realtime facial recognition at conferences, for example, would make my life a lot easier.