I dont use google maps much, but I was using it today and I clicked the "Show my location" button for the first time, then firefox asked for permission and I clicked "share my location", google maps showed my location pretty accurate.

But, how does this system really works? I mean how can google know where I live? I am connecting to the internet with a VPN, so my "public IP" is not from my country, but from sweden, also I use linux and I change the mac of my wireless device, but google still show my location.

I know I can disable this feature setting firefox about:config geo.enabled to false, but I am curious about how google can know where I live even when I dont have a real mac address and my IP is not from my real country.

Basically I'd like to know if this feature works only because of code that exists in chrome and firefox (which spies my system)? I am worried about anyone knowing where I live, I mean... where is my privacy? Part of the fun about the internet is remaining anonymous.