Method, system and computer program for obtaining information about telecommunications devices that transmit signals seeking available Wi-Fi connectivity. One or more Wi-Fi beacons are configured to detect probing signals from any telecommunications device in its range, a processor at each Wi-Fi beacon extracts an identifier of each telecommunications device from detected probing signals and each Wi-Fi beacon is associated with the identifier of any telecommunications devices whose probing signals have been received by that Wi-Fi beacon to thereby determine the presence and optionally position of any telecommunications devices within the range of the Wi-Fi beacon. The telecommunications devices are not involved in the method other than providing in their usual manner of operation, probing signals containing identifiers.