Affect theory raises greater awareness of non-representational forces in social life that can shape different levels of subjectivity in ways that may not be immediately known to the subjects. In outbreaks of mass hysteria when subjects are suddenly exposed to bizarre and extreme behaviors, the question of affect becomes a key to understanding how their subjectivity is impacted by situations that seemingly slip immediate control. Hysterical subjectivity occurs not from unconscious forces but from affective contagions spreading throughout network assemblages. These are flows of fear and conflict that with non-conscious influences constitute the new forces of mass encounters. In these encounters, micro-flows of imitation are automatized by various assemblages of intention and action to produce repeatable contagions of affects and behaviors. The occurrence of the COVID-19 pandemic demonstrates the power of these flows as facilitating a global affectivity of mass hysteria. It is an affectivity in which imitation takes on a central role as technology of the social for the behavioral control of mass populations. Ubiquitous mask-wearing in the pandemic is not only seen as a prophylactic against viral infection but also intended as a mandated form of mimicry for propagating the new politics of virality. These are politics that empower fear as an agent of cascading contagions paralyzing social, cultural, and economic life around the world.