1. A method for detecting crowds in a location tracking system, the method comprising: defining, using at least one computer system, a grid in two dimensions in a geographic coordinate system, the grid having a predetermined spacing in each dimension between grid points of the grid; receiving a geographic location from each of a plurality of objects, the geographic location including coordinates in each of the two dimensions in the geographic coordinate system; comparing the geographic locations to the grid points and defining as an active grid point each of a plurality of the grid points that are positioned within the predetermined spacing to at least one of the objects in each of the two dimensions; storing each of the active grid points using at least one memory device of the at least one computer system; receiving an updated geographic location from a first one of the objects; and checking, by at least one processing unit of the at least one computer system and using the updated geographic location and the geographic locations of other ones of the objects, for an existence of a crowd by determining whether there are four or more times a predetermined threshold number of the objects that are located within the predetermined spacing in each of the two dimensions to a first one of the active grid points that is within the predetermined spacing in each of the two dimensions to the updated geographic location.