The isp that I have has a flaw where if you manualy set your tcpip settings to that of another pc within your subnet you could "steal" that persons ip - disabling them from the internet - now if they call the isp; then they would trace the ip back to the MAC and disable that MAC but my question is if they only trace the ip if the person calls the isp would it be traceable if the person doesnt call the isp