http://blog.appboy.com/2010/08/facebook-and-its-500-million-users-join-the-location-game/

Just in case you have not yet noticed, no one wants privacy anymore. Facebook is dominating the Web with its whopping 500 million users, Twitter is flourishing with people sharing every last detail about their lives, Foursquare and Gowalla are booming in popularity, and now, this whole lack of privacy is reaching totally new levels.