This section presents four chapters reviewing the current state of research on cyberbullying, digital cruelty, and online hate speech, the impact of the coronavirus pandemic, and their association with mental health. Researchers in this field face challenges, including the different forms that cyberbullying and hate speech can take, the definition of cyberbullying, and how future technologies like Artificial Intelligence may change the research landscape. Two chapters in this section discuss digital forms of social cruelty, including cyberbullying, and how these currently manifest on social media and (likely) impact mental health. Other chapters examine the impact of the global pandemic on cyberbullying and how online bias has infiltrated and influenced cyberbullying and its serious impact on users. Among other points, these chapters discuss online hate speech and how youth may be differentially vulnerable (e.g., LGBTQ youth). This Introduction briefly discusses how the definition of cyberbullying may change and how new technologies may alter how digital cruelty is experienced by youth.