I just noticed last week that Google Maps knew the location of my laptop computer, even though I had never told it where I was. After a bit of sleuthing, it turns out that Google probably got this information when a someone with an Android phone visited. The phone sniffed my WiFi ports, read the GPS location, and reported this back to Google location services. They did this without my knowledge, and without my permission.
randomWalks @randomWalks