Online Social Networks (OSNs) became part of the everyday life for many people around the world. They are one of the main channel through which information can spread at lightning speed. Thanks to this fact, people use them for the most disparate reasons, such as sources of information in place of newspapers, to receive emotional or technical support, or to share their ideas and opinions to satisfy their need of sociality.

Since their introduction, people questioned these services because they are affected by several problems. These problems include: preservation of the users’ privacy, fake news diffusion, diffusion of illegal pieces of content, censorship vs free speech, economic value redistribution, security vs trust, and so on. The aim of this workshop is to partially trying to overcome these problems by setting up a platform for researchers to publish their contributions.

The contributions can point to: innovative methods and algorithms for social graph mining, which can be helpful to develop more efficient information diffusion techniques; the problem of privacy, and how can be enforced in these system is current, and in particular the relation between security, trust and privacy is crucial in the scenario of OSNs; the decentralisation and its impact on the implementation of social services; how Artificial Intelligence techniques that respect the privacy of the users can be implemented; technologies that enable the metaverse.

• Information systems → Social networks; • Networks → Online social networks; Trust; • Information systems~Web and social media search; • Human-centered computing → Collaborative and social computing;

Social Networks and Media: analysis and mining, Decentralization, Blockchain, AI for Social Media

Barbara Guidi, Laura Ricci, and Andrea Michienzi. 2022. OASIS’22: 2nd International Workshop on Open Challenges in Online Social Networks. In Proceedings of the 33rd ACM Conference on Hypertext and Social Media (HT '22), June 28-July 1, 2022, Barcelona, Spain. ACM, New York, NY, USA 2 Pages. https://doi.org/10.1145/3511095.3532574

The diffusion of Online Social Networks (OSNs) has had a profound effect on the way we interact and a deep impact on society and business. Social Medias have helped people to communicate, breaking down the geographical barriers that restricted communication. Through social networks, virtual communication, sharing of information, community participation is possible even among people in uncomfortable conditions. Today, Social Media are one of the main parts of daily life by affecting sociality, but they are also important channels through which information travels faster than ever. Analysis of OSN can help to foresee events to manage critical scenarios. The rapid growth in popularity has opened new challenging problems which involve numerous fields in computer science. These issues have implications on social graph analysis [4], trust and security [5], and so on. Moreover, privacy issues and the usage of mobile devices has opened new research fields in the design of decentralised online social networks, which can be considered one of the most important challenges [1]. Furthermore, the current improvement concerning the study and the proposal of new approaches for Social Networks and Media involve not only complex network analysis, and, in particular, the decentralisation of social services [2, 3], but also the introduction of innovative technologies such as Artificial Intelligence and Virtual/Mixed Reality to ferry humankind towards the next generation Online Social Networks. The workshop targets researchers, doctoral students, people from industry and other people interested in discussing, reflecting and networking on central themes associated with the development and the use of social networks. Papers on both theoretical and design aspects of social networks are welcome, which describe and evaluate novel design methods and system prototypes. The workshop also welcomes work in progress and position papers.

Contributions cover, but are not limited to, the following topic areas:

Social Networks Design and Analysis

Security, Trust, and Privacy in Social Networks and Media

Decentralized Social Networking applications: P2P, Cloud, and Mobile

Blockchain Social Media: analysis and applications

Social Sensing and Sentiment Analysis

Incentive systems for OSNs

Data Mining for OSNs and Media

Dynamic Network Analysis in OSNs

AI for OSNs and Media

Social Dynamics

Accessibility for the Web and Media

Mobility Data and Analysis for Social Media

Ethics in Social Media Analysis

Virtual/Mixed Reality for the Metaverse

During the workshop, Nicolas Kourtellis will give a keynote talk concerning some of the major highlights regarding his research field. Nicolas Kourtellis is a Principal Research Scientist at Telefonica R&D, Barcelona, Spain. He holds a PhD in Computer Science & Engineering from the University of South Florida, USA (2012). Before Telefonica R&D, he did research at Yahoo Labs, USA, on online user privacy and behavior modeling, Internet measurements and distributed systems, with 70+ published peer-reviewed papers and 6 filed patents

In the keynote talk, Nicolas Kourtellis will discuss his recent efforts to study user activity on popular OSNs and other websites, as well as the continuous user tracking from such platforms, potentially leading to severe implications on their privacy. In particular, firstly, he will cover his extensive studies to detect and characterize inappropriate content and behavior on social media such as Twitter and YouTube, including manifestation and propagation of aggressive, abusive or bullying behavior, fraudulent crowdfunding campaigns and fake news. Then, he will discuss in depth how tracking of users from online entities (first and third-parties), initiated by various advertising protocols, leads to increased (GDPR) violations in the privacy of said users, with typical offenders being popular OSNs and other online ad-platforms. He will conclude with future challenges in the space of OSNs.

Barbara Guidi is currently an Assistant Professor at the Department of Computer Science of the University of Pisa. She received her B.Sc. and M.Sc. in Computer Science from the University of Pisa, Italy, in 2007 and 2011, respectively. She received her Ph.D. degree in Computer Science from the University of Pisa, in 2015. She was a Co-Chair for the conference EAI GoodTechs 2017, and Co-Chair of several workshops. She has been involved in the TPC of several International conferences and workshops, and has been a reviewer for relevant journals, such as IEEE Access, and Concurrency and Computation: Practice and Experience (CCPE). She received three Best Paper Awards: at the International Conference DCNET 2013, at the workshop LSDVE 2017, and at LSDVE 2018. Her current research interests include distributed systems, P2P networks, complex networks, Social Network Analysis, Decentralized Online Social Networks, dynamic community detection, and the Blockchain technology.

Laura Ricci received the M.Sc. in Computer Science from the University of Pisa in 1983 and the Ph.D. from the same University, in 1990. She is currently Associate Professor at the ”Department of Computer Science”,”University of Pisa”, Italy. Her research interests include distributed systems, peer-to-peer networks, cryptocurrencies and blockchains and social network analysis. In these fields, she has co-authored 100+ papers published on international journals and conference/workshop proceedings. She has served as program committee member and chair of several conferences. In particular, she has been Program Chair of the 19th edition of ”DAIS, International Conference on Distributed Applications and Interoperable Systems”. She is the organizer of the LSDVE, Large Scale Distributed Environments workshop, held in conjunction with EUROPAR conference. She has been involved in several research projects and she is currently the local coordinator of the H2020 European Project ”Helios: A contect aware Distributed Networking Framework”

Andrea Michienzi got a Bachelor degree in December 2015 followed by a Master degree in October 2017 in Computer Science at the Università di Pisa. Starting from November 2017, he is a PhD student at the department of Computer Science at the Università di Pisa, a position he is still holding at the present times. Starting from April 2018, he is an associate researcher at the ISTI-CNR in Pisa in the High Performance Computing lab. His main research interests are distributed systems and complex network analysis. More in detail, he is currently investigating techniques for community detection throughout time, focusing on exploiting these mechanisms for the development of Distributed Online Social Networks. Moreover he is starting to investigate other blue-sky research topics, such as dynamics of socio-economic networks and influencer and area-of-influence detection in online social networks.

Aaron Beach, Mike Gartrell, and Richard Han. 2009. Solutions to security and privacy issues in mobile social networking. In 2009 International Conference on Computational Science and Engineering, Vol.4. IEEE, 1036–1042.

Barbara Guidi, Andrea Michienzi, and Laura Ricci. 2020. A graph-based socioeconomic analysis of steemit. IEEE Transactions on Computational Social Systems 8, 2 (2020), 365–376.

Barbara Guidi, Andrea Michienzi, and Laura Ricci. 2020. Steem blockchain: Mining the inner structure of the graph. IEEE Access 8(2020), 210251–210266.

Andrea Michienzi, Barbara Guidi, Laura Ricci, and Andrea De Salve. 2021. Incremental communication patterns in online social groups. Knowledge and Information Systems 63, 6 (2021), 1339–1364.

Chi Zhang, Jinyuan Sun, Xiaoyan Zhu, and Yuguang Fang. 2010. Privacy and security for online social networks: challenges and opportunities. IEEE network 24, 4 (2010), 13–18.

Permission to make digital or hard copies of part or all of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for third-party components of this work must be honored. For all other uses, contact the owner/author(s).

HT '22, June 28–July 01, 2022, Barcelona, Spain

© 2022 Copyright held by the owner/author(s).

ACM ISBN 978-1-4503-9233-4/22/06.

DOI: https://doi.org/10.1145/3511095.3532574