A data placement device creates a similarity index for each of computational resources based on a similarity between each of the pieces of acquired data and each of the pieces of data stored in the computational resources. In one embodiment, the optical sensing device monitors a concentration of toner particles captured in a filter element within an electrostatic imaging device. In the methods of the present invention, the called party dials a code comprised of a series of digits, which triggers the switching node associated with the called party to generate a series of messages, at least one of which encompasses the originating telephone number of the unwanted call.