Petabytes of data about human movements, transactions, and communication patterns are continuously being generated by everyday technologies such as mobile phones and credit cards. In collaboration with the mobile phone, internet, and credit card industries, Eagle and colleagues are aggregating and analyzing behavioral data from over 250 million people from North and South America, Europe, Asia and Africa. Eagle discusses projects arising from these collaborations that involve inferring behavioral dynamics on a broad spectrum of scales from risky behavior in a group of MIT freshman to population-level behavioral signatures, including cholera outbreaks in Rwanda and wealth in the UK. The research group is developing a range of large-scale network analysis and machine learning algorithms that will provide deeper insight into human behavior.