Robert Siciliano, CEO of IDTheftSecurity, noted recently on the McAfee blog that apps like, "Foursquare, Facebook and Yelp allow you to check in' at places using your mobile phone, and then share your location with friends or on social networks
http://www.networkworld.com/news/2013/101813-every-move-you-275004.html?source=nww_rss