The talk will introduce to some of the opportunities and challenges of social media data analysis by reviewing key methods and issues in data retrieval and mining. The primary focus of the talk will be the study of 1,000 Danes’ private Facebook data from 2007-2014 and the development of the software Digital Footprints (www.digitalfootprints.dk). Anja Bechmann will present and discuss preliminary findings on questions such as do young people post less on Facebook, does the Pareto principle apply to Facebook posting patterns and what kind of secret, open and closed groups are Danes and South Koreans members of.