This study conceptualises networked events as a platform-oriented view of media events by initiating a taxonomy of bottom-up construction.Focusing on computer-mediated event construction that may involve live delivery, permeate digital platforms, and attract user engagement prior to, during, and after the occurrence of ceremonial or disruptive events, the study argues that networked events can be characterised by polymorphism-i.e., presence of distinct patterns of uptake and different interactional orientations within the same space of interactions, such as hashtags. Using a network dataset of 221,105 tweets that included the hashtag #HimToo which was used extensively during the US Senate judiciary committee hearing that investigated claims of sexual harassment against President Trump's Supreme Court nominee Brett Kavanaugh, the study demonstrates that three types of construction-i.e., actor-centric, memetic, and metaconstruction-causes polymorphism in Twitter engagement related to the event.