Abstract: The invention enables the surveillance of computer-like devices while they are connected to a communications network. This latter includes a Network Surveillance Server (NSS). Upon joining said communications network, a device is first required to log-in to NSS. After which, NSS polls it while connected on the network so that an alarm can be issued, from NSS, to a central surveillance unit, if the device fails responding to polling. Hence, prior to leaving the communications network, the computer-like device is also required to log-out to NSS. Thus, as long as it is connected to the communications network, the computer-like device is watched.