Geo-social networking allows people to share their geographic locations through social networks. Popular geo-social networks like Foursquare let users check-in at locations and collect badges, while also linking to Twitter. These networks raise privacy concerns but provide benefits like knowing what friends are doing and getting recommendations. Geo-social networking growth has been massive and built-in GPS will expand it further. Facebook also entered the space with "Facebook Places", experiencing over 700% growth worldwide. Questions remain around privacy and how personal information shared could be misused.