One significant problem with studying social systems is the difficulty of forming and testing theories; social systems are not easily manipulated or controlled and large-scale systems cannot be reproduced in a lab setting.[10] However, the rapid increase in the availability of digital data over the last decade gives scientists studying the behaviors of social systems very detailed and much more holistic pictures of how social systems respond to various events and how networked social systems behave.[11] Additionally, the development and popularity of social media platforms such as Facebook and Twitter offer new ways to study the evolution of social systems and social networking behaviors with social graphs.[12] Even though the behaviors of these systems may be surprising or not yet well understood, the digital age offers a new frontier for the study of social systems.[13]