Abstract: A method of verifying user characteristics based on data relating to the user's mobile device, the method being performed at a mobile or wireless telecommunications network and comprising the steps of receiving at a data analysis system of the mobile or wireless telecommunications network via a computer network a query from a remote computer system; the data analysis system retrieving data relating to the user's mobile device from a data store system of the mobile or wireless telecommunications network, wherein the retrieved data is selected based on the query; the data analysis system processing the retrieved data to obtain an answer to the query; and transmitting the answer to the remote computer system.