Privacy-Preserving Techniques for Online Social Networks Data

Introduction

The number of Internet users is rapidly increasing, and as a result, the number of online social networking sites is also growing. Online social networks (OSN) are digital platforms that allow individuals to connect, communicate, and share information with each other over the internet. These networks enable users to create personal profiles, interact with other users through various means such as messaging, comments, and likes, and share content such as photos, videos, and status updates (Jain et al., 2021). Social networking involves the use of platforms such as Facebook, WhatsApp, Instagram, and Twitter to communicate with friends, family, colleagues, or even strangers sharing similar interests, hobbies, beliefs, and goals. According to January 2023 statistics (Dixon, 2023), Facebook is the most popular social network, with 2.958 billion monthly active users out of the 5.18 billion internet users. YouTube accounts for 2.514 billion users, while WhatsApp and Instagram have two billion users. Twitter has 556 million active monthly users. Although social media has many benefits, there is growing concern regarding user data privacy.

In general, the data gathered by online social network operators are rich in relationships and content, which is valuable to many third-party consumers. The data types in online social networks include Service Data and Behavioral Data. Service Data includes compulsory information that users need to upload as a requirement to join a social network, such as legal name, age, gender, email, and phone numbers. These are essential details for user identification and account creation. On the other hand, Behavioral Data is collected based on user behavior, encompassing actions such as what the user does, where, when, and with whom. Behavioral data provides insights into user interactions and activities within the social network. Unfortunately, online social network providers often utilize users' sensitive data to generate revenue, such as their interests, hobbies, and profiles, to tailor precise advertisements. This practice sometimes extends to divulging sensitive data to third parties (e.g., data brokers) without obtaining explicit informed consent (Wainakh et al., 2019). Moreover, due to users' lack of privacy awareness, they may not consider access rights and sharing scope when sharing information on OSNs, which puts their privacy at risk. These settings directly impact who can view and interact with their personal information, and this oversight can lead to negative privacy-related experiences for users (Guo et al., 2023).

On numerous occasions, user data was compromised by unauthorized parties, like the 2018 breach of Facebook tokens, where Cambridge Analytica obtained access to nearly 87 million Facebook accounts (Gao & Li, 2019). Cambridge Analytica used these accounts to sway public opinion in political campaigns without the users’ knowledge or consent (Rodrigues et al., 2023). This has led to a call for stricter regulations and policies to protect user privacy, as well as greater transparency from social media platforms about their data handling practices to ensure user trust and confidence in the digital space. Therefore, it is mandatory to understand the privacy-preserving measures and approaches that can be used to safeguard user information from unauthorized access and misuse in OSNs. This chapter provides a comprehensive review of the various prevalent privacy threats on social media networks, their potential attacks, and their impact on users and OSN companies' reputations. In addition, the chapter will explore the current privacy-preserving mechanisms and techniques in the literature used to mitigate these threats and safeguard users' privacy within this dynamic environment. We have followed the systematic literature methodology of Kitchenham et al. (2009) to ensure selection of pertinent and relevant studies aligns with the objectives of our chapter. Understanding the complex landscape of privacy threats in OSNs and the various measures that can be used to safeguard user privacy can guide future efforts to create a safer and confidential online social networking environment for all users.