We presented at BlackHat Federal the idea of "data seepage": bits of benign data that people willingly broadcast to the world (as opposed to "leakage", which is data people want to hide from the world). Examples of data seepage is what happens when you power-on your computer. It will broadcast to the world a list the list of WiFi access-points you ve got cached on your computer, the previous IP address you used (requested by DHCP), your NetBIOS name, your login ID, and a list of servers (via NetBIOS request) you want connections to.
