Balistic - 12:24 am on Dec 18, 2004 (gmt 0)
Basically the main thing is your ip address, if its not your ip address that you log into adsense control panel with then they cant say that its you. So thats basically it, though they could use the google cookie that is set to also tell if you have clicked your own ads. This is just what i think. Theres not an awful lot they could do i guess in the way of detection.