In the presented work, Internet of Things (IoT) technologies, like sensors and their applications, have been investigated from a socio-technical perspective focusing on civic purposes of the technologies’ use. The aim of the work is to gain a better understanding of civic IoT and its transformative potential for society. Therefore, the overarching research question is: What are the societal implications of the technological object civic IoT? Three application areas identified as highly relevant have been studied: community-based environmental monitoring, sustained engagement of civic tech initiatives, and the “Journalism of Things.” In the first study, the civic IoT initiative Luftdaten.info dedicated to the community-based monitoring of particulate matter in the air was examined. The initiative is organized within limits of technical equipment, resources, and academic knowledge. The case study comprises a media content analysis, a web application analysis, and two expert interviews. The data illustrates that the local air pollution topic is a discursive long-term process striving towards a more sustainable city and community. The findings show that the information provided by Luftdaten motivates certain people to become aware and engaged for their local environment, and some to change their behavior. I found that the initiative itself is managed in a sustainable way being inclusive and resource-saving. The media content analysis shows that events around the emergence of the Luftdaten initiative had a certain influence on the local media agenda. Finally, a data map comparison shows how easily misunderstandings in the representation of monitoring data can occur when taking different decisions during the data analysis and visualization of almost identical datasets. In the second study, two long-lasting civic tech initiatives of global scale were investigated to understand what makes them sustain over time. We conducted two mixed-method case studies of the initiative Luftdaten.info from Germany and the initiative Safecast from Japan. We combined social network analysis and qualitative content analysis of Twitter data with insights from expert interviews. Drawing on our findings, we identified a set of key factors that help the studied civic tech initiatives to grow and last. Contributing to Digital Civics in HCI, we argue that the civic tech initiatives’ scaling and sustaining are configured through the entanglement of (1) civic data both captured and owned by the citizens for the citizens, (2) the use of open and accessible technology, and (3) the initiatives’ public narrative, giving them a voice on the environmental issue. In the third study, Journalism of Things (JoT) as a new paradigm in digital journalism was investigated. Three case studies on recent award-winning journalism projects in Germany were conducted with the analytical lenses of boundary work and objects of journalism. The study comprises interviews with journalists, media content analyses, and observations of virtual public events. The findings suggest four typical phases in JoT projects: formation, data work, presentation, and ramification. Blurred boundaries of journalism towards science and activism become apparent when co-creative JoT teams apply scientific methods and technology design while mobilizing communities. Findings further show that things (or objects) of JoT have implications on the configuration for collaborative arrangements and audience relations. By creating and disseminating new local knowledge on matters of common concern, JoT is also contributing to empowering both journalism and citizens. This dissertation is a cumulative work comprising three peer-reviewed scientific publications.