A monitoring system for response to incidents sensed by at least one sensor of an individual signal unit; said response comprising in a first instance, transmission to a central control facility by a said individual signal unit, of at least a unique identifying code for that individual signal unit, over a communication network; said response comprising in a second instance, transmission of data from said central control facility to one or more recipients nominated by a registered owner of said individual signal unit; and wherein registration of a said individual signal unit and configuration of sensing and of said response is via a web-based interface.