Theoretically there is a possibility that someone could contact each isp on the planet and buy\get a list of all the subscribers...which would easily link to the subscriber (not necessarily the user mind you) but as Shroom said...if u are behind any kind of firewall that translates (NAT) that would rule off any IP's for corporate use...course some apt complexes here in CO use a firewall for the "site" and they share out the net access to the whole place for a price...then again if u use WLAN through a FW then those will also be hidden as well... CP should have a tech\geek forum