The Lifecycle and Cascade of WeChat Social Messaging Groups

Social instant messaging services are emerging as a transformative form with which people connect, communicate with friends in their daily life - they catalyze the formation of social groups, and they bring people stronger sense of community and connection. However, research community still knows little about the formation and evolution of groups in the context of social messaging - their lifecycles, the change in their underlying structures over time, and the diffusion processes by which they develop new members. In this paper, we analyze the daily usage logs from WeChat group messaging platform - the largest standalone messaging communication service in China - with the goal of understanding the processes by which social messaging groups come together, grow new members, and evolve over time. Specifically, we discover a strong dichotomy among groups in terms of their lifecycle, and develop a separability model by taking into account a broad range of group-level features, showing that long-term and short-term groups are inherently distinct. We also found that the lifecycle of messaging groups is largely dependent on their social roles and functions in users' daily social experiences and specific purposes. Given the strong separability between the long-term and short-term groups, we further address the problem concerning the early prediction of successful communities. In addition to modeling the growth and evolution from group-level perspective, we investigate the individual-level attributes of group members and study the diffusion process by which groups gain new members. By considering members' historical engagement behavior as well as the local social network structure that they embedded in, we develop a membership cascade model and demonstrate the effectiveness by achieving AUC of 95.31% in predicting inviter, and an AUC of 98.66% in predicting invitee.Comment: 10 pages, 8 figures, to appear in proceedings of the 25th International World Wide Web Conference (WWW 2016

Mobile Instant Messaging Evidence in Criminal Trials

Mobile instant messaging, such as text messages, are a pervasive aspect of everyday life. The characteristics of the modern mobile instant messaging application, especially in comparison with other forms of more traditional electronic communication platforms, such as e-mail, text messaging, or computer-based instant messaging program, present a variety of evidentiary issues in trial. To be relevant, mobile instant messaging evidence must be connected to a genuine issue at trial and not too attenuated from it. Authentication is also very important in determining whether it may be considered a non-hearsay statement. Although often otherwise admissible, mobile instant messaging evidence may still be inadmissible if its probative value is substantially outweighed by the risk of unfair prejudice or other concerns of fairness. This comment examines the evidentiary issues surrounding the admissibility of the mobile instant messaging evidence in criminal trials, with particular emphases on the issues of authentication and the best evidence doctrine

Key Considerations: Online Information, Mis- and Disinformation in the Context of COVID-19 (March 2020)

This brief sets out practical considerations relating to flows of information, misinformation and disinformation though online media, particularly social media networks, in the context of the COVID-19 pandemic. It details various types of online media, key players and influencers on social media, and strategies for ensuring good information and disrupting mis- and disinformation. It is important to analyse different types of information across different channels, how it is spread and to whom, in order to determine how social media can be harnessed in both positive and negative ways. The WHO recommends proactive communication during a public health emergency that, “encourages the public to adopt protective behaviours, facilitates heightened disease surveillance, reduces confusion and allows for better allocation of resources – all of which are necessary for an effective response”.1 With its global influence, social media requires particular consideration during times of public health emergencies and was highlighted as a key issue by the Social Science Working Group of WHO’s Global Research Roadmap for COVID-19. Timely, accurate communication through all media sources is a critical component of ensuring trust in response activities. The brief was developed for the Social Science in Humanitarian Action Platform (SSHAP) by Anthrologica (Nadia Butler and colleagues). Jennifer Cole (Royal Holloway, University of London) acted as expert advisor. The brief was reviewed by colleagues from the Institute of Development Studies, London School of Hygiene and Tropical Medicine, Nottingham Trent University, Novetta, Internews and GOARN. It is the responsibility of the SSHAP.本简报针对在2019冠状病毒病（COVID-19） 大流行背景下，就信息、错误信息和虚假信息通过网络媒体特别是社交媒体网络而流通，提出了实务的考虑因素。它详细地分析了各种类型的网络媒体，社交媒体的主要参与者和具影响力的人，以及确保良好信息和阻断错误和虚假信息的策略。为了确定如何以正面和反面的方式来驾驭社交媒体，须要分析在不同渠道中流通、不同类型的信息及其传播方式与传播对象。 世界卫生组织(WHO)建议在突发公共卫生事件期间采取积极主动的传播工作，从而“鼓励公众采取保护行为，为升级的疾病监测开道，减少人们無所適從的感觉，并为更有效地分配资源创造条件——这些均为有效应对所必须的”。社交媒体拥有全球影响力，在突发公共卫生事件期间有必要对其特别加以考虑，世界卫生组织COVID-19全球研究路线图社会科学工作组也将它列为一项关键议题。通过所有媒体渠道进行及时、准确的传播，是确保民众对应急活动信心的一项关键部署。 Anthrologica（Nadia Butler和同事）为人道主义行动中的社会科学平台(SSHAP)编制了本简报，Jennifer Cole（伦敦大学皇家霍洛威学院）担任专家顾问。英国国际发展研究院（IDS）、伦敦卫生与热带医学院、诺丁汉特伦特大学、Novetta、Internews和全球疫情警报和反应网络（GOARN）的同事对本简报进行了审阅。SSHAP对本简报内容负全责。Cette note stratégique énonce des considérations pratiques inhérentes aux flux d’informations, de fausses informations et de désinformation qui circulent dans les médias en ligne, en particulier sur les réseaux sociaux, dans le contexte de la pandémie de COVID19. Elle présente en détails différents types de médias en ligne, des acteurs clés et influenceurs sur les réseaux sociaux, ainsi que des stratégies visant à garantir la diffusion d’informations fiables et l’interruption de la diffusion de fausses informations et de désinformation. Il est essentiel d’analyser plusieurs types d’informations sur différents canaux, ainsi que la façon dont elles sont diffusées et à qui, afin de déterminer comment les réseaux sociaux peuvent être exploités à la fois de manière positive et négative. L’OMSPlease note: there is an accompanying infographic summarising the key points from the briefing.UNICE

Characterizing Attention Cascades in WhatsApp Groups

An important political and social phenomena discussed in several countries, like India and Brazil, is the use of WhatsApp to spread false or misleading content. However, little is known about the information dissemination process in WhatsApp groups. Attention affects the dissemination of information in WhatsApp groups, determining what topics or subjects are more attractive to participants of a group. In this paper, we characterize and analyze how attention propagates among the participants of a WhatsApp group. An attention cascade begins when a user asserts a topic in a message to the group, which could include written text, photos, or links to articles online. Others then propagate the information by responding to it. We analyzed attention cascades in more than 1.7 million messages posted in 120 groups over one year. Our analysis focused on the structural and temporal evolution of attention cascades as well as on the behavior of users that participate in them. We found specific characteristics in cascades associated with groups that discuss political subjects and false information. For instance, we observe that cascades with false information tend to be deeper, reach more users, and last longer in political groups than in non-political groups.Comment: Accepted as a full paper at the 11th International ACM Web Science Conference (WebSci 2019). Please cite the WebSci versio

Exploring the Process of Fresh Produce Supply Within a Platform Ecosystem During City Lockdown Period

While the existing literature focusing on how organizations collaborate within ecosystems to overcome institutional logic conflicts and the information systems enabled inter-organizational cooperation, less is known on how information systems develop during crises and enable effective collaboration among stakeholders. Through an in-depth case study of Shenzhen Company H (pseudonym) platform ecosystem, we present an IT-enabled fresh produce supply process. Our findings reveal that this process unfolds across four dimensions - iterative IT tailoring, progressive system synergy, facilitative IT confluence, and user-attuned technological adaptation. Based on these dimensions, we propose an IT-enabled platform ecosystem orchestration mechanism in crisis situations. These mechanisms also offer practical implications not only for organizations\u27 strategies when facing crises but also for the enhancement of their daily operational competence

Practical Traffic Analysis Attacks on Secure Messaging Applications

Instant Messaging (IM) applications like Telegram, Signal, and WhatsApp have become extremely popular in recent years. Unfortunately, such IM services have been targets of continuous governmental surveillance and censorship, as these services are home to public and private communication channels on socially and politically sensitive topics. To protect their clients, popular IM services deploy state-of-the-art encryption mechanisms. In this paper, we show that despite the use of advanced encryption, popular IM applications leak sensitive information about their clients to adversaries who merely monitor their encrypted IM traffic, with no need for leveraging any software vulnerabilities of IM applications. Specifically, we devise traffic analysis attacks that enable an adversary to identify administrators as well as members of target IM channels (e.g., forums) with high accuracies. We believe that our study demonstrates a significant, real-world threat to the users of such services given the increasing attempts by oppressive governments at cracking down controversial IM channels. We demonstrate the practicality of our traffic analysis attacks through extensive experiments on real-world IM communications. We show that standard countermeasure techniques such as adding cover traffic can degrade the effectiveness of the attacks we introduce in this paper. We hope that our study will encourage IM providers to integrate effective traffic obfuscation countermeasures into their software. In the meantime, we have designed and deployed an open-source, publicly available countermeasure system, called IMProxy, that can be used by IM clients with no need for any support from IM providers. We have demonstrated the effectiveness of IMProxy through experiments