From the page:
"android map exposes the data that Google has been collecting from virtually all Android devices and street view cars, using them essentially as global wardriving machines. You can use this tool to accurately locate virtually any router in the world, as well as position iPhones and Android phones.
When the phone detects any wireless network, encrypted or otherwise, it sends the BSSID (MAC address) of the router along with signal strength, and most importantly, GPS coordinates up to the mothership
This page allows you to ping that database and find exactly where any wi-fi router in the world is located. Note that iPhones also send this BSSID and Cell Tower Information up to Apple, as well."
The search result looks like this:
Note that, Technitium MAC Address Changer (TMAC) cannot change MAC Address of your router. You can change it from web interface the device provides. MAC address changing feature might not be available in all routers though.