An anonymous reader writes: Yahoo has filed a patent for advertising billboards outfitted with a wide array of sensors -- including drone-based cameras -- which would use facial and vehicle recognition, data brokers, cell-tower information and social network information to attempt to identify worthwhile advertising targets and aim personalized ads at them as they pass on foot or in cars. The scheme, which was submitted on October 6th, anticipates using the same kind of micro-auction processes that currently determine which ads users see in webpages and mobile apps. The implementation of public ad-targeting brings up some fascinating and chilling prospects, as users find that the ads which "bloom" around them betray much about their private lives. Yahoo provides an example via its patent application: "According to one example, a digital billboard adjacent a busy freeway might be instrumented with or located near traffic sensors that detect information about the context of the vehicles approaching the billboard, e.g., the number and average speed of the vehicles. Such information might be used in conjunction with information about the time of day and/or the day of the week (e.g., Monday morning rush hour) to select advertisements for display that would appeal to an expected demographic and to display the advertisements for durations that are commensurate with the level of traffic congestion." The patent application also mentions how it will gather required information from individuals: "Various types of data (e.g., cell tower data, mobile app location data, image data, etc.) can be used to identify specific individuals in an audience in position to view advertising content. Similarly, vehicle navigation/tracking data from vehicles equipped with such systems could be used to identify specific vehicles and/or vehicle owners. Demographic data (e.g., as obtained from a marketing or user database) for the audience can thus be determined for the purpose of, for example, determining whether and/or the degree to which the demographic profile of the audience corresponds to a target demographic."