A method of determining an identity of a called or calling user of a communication propagated over a communications network, the method comprising: determining at least one characterizing feature of an outgoing communication to a called user or an incoming communication from a calling user transmitted over the communications network that is associated with a first user; identifying an incoming or outgoing communication respectively of a second user of the communications network having a least one characterizing feature that matches the at least one characterizing feature of the outgoing or incoming communication associated with the first user; and determining an identity of the called or calling user to be that of the second user.