"The integration of various federally required and state mandated do-not-call lists for telemarketers into a system that automatically blocks outgoing calls from a number of companies ("Customer Companies") taking into account factors such as preexisting customers which may legally be contacted is disclosed. The system reviews outgoing calls by a telemarketer, compares it to the general do-not-call lists and the specific customer company do-not-call list and override permitted call list to make a determination if the call should be completed. This integration is due to the incorporation of a general purpose computer in a central location that is connected to all the major telephone carriers switch cluster locations and operated by a service provider. The "do-not-call" database of originating/destination pairs, as well as the logic for blocking or permitting telephone calls, is stored in this computer. This computer makes all blocking decisions in real-time based on the originating and destination number combinations of the call."〔(Patent Abstract )〕