1. A method of estimating the likelihood of a Wi-Fi enabled device being located within an estimated geographical area, the method comprising: identifying at least one Wi-Fi access point in range of the Wi-Fi enabled device based on signals received by the Wi-Fi enabled device transmitted by the at least one Wi-Fi access point; consulting a reference database to determine for the at least one Wi-Fi access point from which signals were received a last-known estimated position of the at least one Wi-Fi access point and time information associated with said last-known position for describing a most recent time when the at least one Wi-Fi access point was observed to be at said last-known estimated position; and estimating the likelihood of the Wi-Fi enabled device being located within an estimated geographical area based on at least one of: the last-known position and the associated time information, and a number of Wi-Fi access points from which signals were received.