@leeloo @reflex @Life_is @CoMaps The opt-in is publicly broadcasting an SSID from a Wi-Fi AP. Modern Wi-Fi APs explicitly support aiding positioning. It's part of why they exist now and they provide it as a public service for everyone to use. Wi-Fi RTT is not limited to authenticated clients but rather Wi-Fi APs help any client with positioning. By running a Wi-Fi AP publicly broadcasting an SSID, you're participating in a decentralized system for non-satellite-based positioning.