Indisputably, the Web has revolutionized the way people receive, consume, and interact with information. At the same time, unfortunately, the Web offers a fertile ground for amplifying socio-technical issues like the spread of hateful content and false information; hence there is a pressing need to develop techniques and tools to understand, detect, and mitigate these issues on the Web. In this talk, I will present our data-driven quantitative approach towards understanding such emerging socio-technical problems, focusing on the spread of hateful content targeting specific demographic groups. Also, I will present our work on understanding mitigation strategies employed by social networks (i.e., moderation interventions) and assessing their effectiveness towards reducing the prevalence and impact of these issues on the Web.