1. A method of estimating a likelihood of a Wi-Fi enabled device being located within an estimated geographical area determined by a positioning system, the method comprising: identifying Wi-Fi access points in range of the Wi-Fi enabled device based on signals received by the Wi-Fi enabled device transmitted by the Wi-Fi access points; consulting a reference database to determine for each of a plurality of the Wi-Fi access points for which signals were received a last-known estimated position of the Wi-Fi access point; determining that at least a first set of the Wi-Fi access points for which signals were received have potentially moved from their corresponding last-known estimated positions based on the last-known estimated positions for at least a second set of Wi-Fi access points for which signals were received, each access point of the second set of Wi-Fi access points being different from each access point of the first set of Wi-Fi access points; and estimating, based on the number of Wi-Fi access points of the first set and the number of Wi-Fi access points of the second set, the likelihood of the Wi-Fi enabled device being located within the estimated geographical area.