Microsoft has restricted its Wi-Fi-powered geolocation database after a researcher investigating Wi-Fi geolocation and position tracking raised privacy concerns about the information recorded. This follows a similar move from Google, amidst identical privacy complaints.
A number of companies including Microsoft, Google, and Skyhook operate Wi-Fi geolocation databases as a means of providing quick and reasonably effective location information to phones, tablets, and laptop computers. Every Wi-Fi and Ethernet device has a unique identifier called a MAC address. Wi-Fi access points broadcast their MAC addresses so that any nearby machines can see the access point and connect to it. Companies building geolocation databases collect access point MAC addresses and GPS locations, then publish this information online. (Community projects such as Wigle accumulate similar databases.)