Check this article by Jami Makan:
..we hope you don’t mind being tracked offline, too.”
In August, Facebook launched Places, a tool that lets you “check in” at real-life locations, such as restaurants and concert venues, with the help of the GPS on your smartphone. The idea: to let friends know where you are. Though just 4 percent of Americans use location-sharing services, critics warn they can make users vulnerable. Privacy experts cite two problematic Places features: One lets users register virtually any location with the service, even someone else’s home or office; the other lets friends check you into locations unless you disable the setting. That means other Facebook users may know where you live or where you are, even if you haven’t posted that info yourself. Kurt Opsahl, a lawyer with the Electronic Frontier Foundation, encourages users where possible to control the settings that allow for such location updates.
