1. An apparatus, comprising: an input device; a communication module; an image sensor; a processor; and memory coupled to the processor and storing instructions that, when executed by the processor, cause the apparatus to: capture an image of an advertisement via the image sensor, the advertisement containing a watermark that is substantially hidden from a human observer; extract encrypted information, the encrypted information comprising an encrypted version of a telephonic reference, from the watermark in the captured image of the advertisement at least in part by filtering the captured image of the advertisement to extract the encrypted information from the watermark; and initiate a telephonic connection using the telephonic reference, and transmit via the communication module a first transmission to a server system, the first transmission comprising at least a portion of the encrypted information.