1 Introduction
Social networks (SNs) are pervasive and indispensable in our everyday life. Due to the contribution of massive behavioral data, SNs have exerted an enormous influence on various research fields, e.g., sociology [1], economics [2] and epidemiology [3]. Cleverly, different SNs supply an individual with different functions, which activates the signups of several SNs for the same individual. For instance, in China, people use RenRen, a Facebook-style but autonymous SN for blogs, and Sina Microblog for sharing the statuses. Theoretically, the integration of users’ behaviors from all these SNs can be beneficial for all these studies on SNs. This is because these cross-platform investigations on SNs merge various SN platforms to create richer raw data and more complete SNs for social computing tasks. Additionally, they enable an all-sided analysis on user behaviors. Accordingly, exploration of this topic lays a foundation for current, as well as further, studies on SNs.