The articles in this special issue focus on the emerging effects that social media can have on the real world. Social media has quickly become not just ubiquitous, but also integral to society. A large portion of social media's quick ascent was due to its modeling of real-world relationships, meaning the offline world informed the development and adoption of the online world. Recently, however, it has become apparent that this effect is not a one-way street. For example, the spread of mis- and disinformation, the spread of conspiracy theories, and the rise of extremism can all be attributed, in part, to social media. Most previous research has studied the real world and social media in isolation. However, these worlds are interconnected with each world having a substantial impact and influence on the other. For instance, hateful rhetoric disseminated via social media can encourage physical meetings that can quickly transform rhetoric into violent actions. Overall, it is of paramount importance, as a research community, to devote research resources into understanding and analyzing the exogenic effects of social media to the real world with the goal to further improves our lives.