If you use the HTML5 Geolocation Api in firefox and have no GPS attached to get your current position, firefox uses the nearby wlan ssids to get your position. Firefox sends the ssids via Geolocation Network Protocol to http://www.google.com/loc/json and gets a lat/long in response. You can modify the server via
about:config with the preference key
The chrome geolocation works the same way. But I cannot find a setting (no about:config in chrome) where I can change the server for ssid -> location mapping. Is it possible to change the server and where do I change the setting?