There's No Hiding Your WLAN from Google

Concern is rising about the amount of information that Google and other organizations are collecting about wireless local area networks (WLAN). The latest news from experts brings little comfort: it's impossible to make your own wireless network completely invisible to others.

All network-ready devices possess a unique identifier. "That's the MAC address. And the WLAN router transmits it constantly," explains Juergen Kuri from German computer magazine c't. The MAC address is necessary for network-capable devices to be able to communicate with each other at all.

Google claims that its search for WLAN networks has nothing to do with breaking into networks, Kuri says. It is instead intended as a way of establishing local maps of WLAN locations. A map of that kind could, for example, allow smartphone users to determine their location independently of GPS, and then use location-specific services. "The WLAN doesn't provide any location data of its own at all," Kuri says. It is instead added by the organization searching for WLAN.