In the everyday practice of online communication, we observe users deliberately reporting abusive content or opposing hate speech through counterspeech, while at the same time, online platforms are increasingly relying on and supporting this kind of user action to fight disruptive online behavior. We refer to this type of user engagement as online civic intervention (OCI) and regard it as a new form of user-based political participation in the digital sphere that contributes to an accessible and reasoned public discourse. Because OCI has received little scholarly attention thus far, this article conceptualizes low- and high-threshold types of OCI as different kinds of user responses to common disruptive online behavior such as hate speech or hostility toward the media. Against the background of participation research, we propose a theoretically grounded individual-level model that serves to explain OCI.