A method that detects unwanted calls based on information shared between a first telecommunications network provided by a first service provider and a second service provider providing a second telecommunications network including receiving, by a data-processing system, a request to provide a telecommunications service to the first telecommunications network, the request being received by the first telecommunications network from a user of the first telecommunications network through a first gateway, and wherein the request comprises a calling party identification that identified a calling party and a called party identification that identified a called party. The method further includes examining, by the data-processing system, statistics relating to requests for telecommunications services; and generating, by the data-processing system, a first signal when the called party identification in the request appears in the statistics in excess of a predetermined first number of instances within a predetermined first time interval.