I have to say for a few weeks i seen this topic coming sooner or later...

Recently i purchased a cheap android device for my wife, and as she is on pay as you go contract i also delete the access point to prevent the phone from going online via the phone access point, but she can still get to the web via our wifi, the problem i notice straight away with the android phone is that most applications try to retrieve your wifi information for position and location and the gps information build into the phone alone doesn't seem to be enough...

the problem with google and other companies gathering this kind of information is that google then recognises your router details and with the rest of information collected they basically get your physical location and make this info available for anyone to cross reference for example to view your location via street view, as it has been demostrate recently by some hackers, in think in particular firefox allows web sites to anonymous gather your router information... which not only google most likely already gathered when they were going around the streets to capture the street view images but also from the actually applications anonymously gathering collecting this kind of information... basically as it has been demonstrate a dodgy script running on a site can gather this info.