Open call articles [Editor´s Note]

For the IEEE Network September/October issue, in addition to part 2 of the Special Issue on Open Source for Networking: Tools and Applications, we are also including six accepted open call articles. The first article, "Are the Popular Users Always Important for the Information Dissemination in Online Social Networks?" by Sheng Wen et al., verifies the importance of popular users in online social networks (OSNs). The results are counterintuitive. First, for the dissemination speed, a large number of users can swiftly distribute information to the masses, but they are not highly connected users. Second, for the dissemination scale, many powerful forwarders in OSNs cannot be identified by the degree measure. Furthermore, it is concluded that to control dissemination, popular users cannot capture most bridges of social communities.