Within the past decade, Internet traffic has shifted dramatically from HTML text pages to multimedia file sharing [1] as illustrated by the emergence of large-scale multimedia social network communities such as Napster, flickr, and YouTube. For example, a study showed that in a campus network, peer-to-peer file sharing can consume 43% of the overall bandwidth, which is about three times of all WWW traffic [2]. This consumption poses new challenges to the efficient, scalable, and robust sharing of multimedia over large and heterogeneous networks. It also significantly affects the copyright industries and raises critical issues of protecting intellectual property rights of multimedia.This recent increase in Internet traffic adversely affects the user experience for people all across the world. To improve the efficiency of data transmission within multimedia social networks, we must analyze the impact of human factors on multimedia networks, that is, how users interact with and respond to