Design research has recently turned the attention to how designers contribute to the organization of publics when designing objects. This also raises the question of what kind of “good” public is being pursued. In this article, we argue for the importance of taking pre-existing normative projects into account to avoid approaching publics as yet another instantiation of “users” of design objects. We develop the argument by discussing our recent attempt at designing an online data visualization tool for public use. Instead of inviting potential future users of our tool to a design workshop, we decided to adopt an ethnographic interest in the existing “goods” that guided the publics for which we wanted to design. Based on explorations of three sites, we found our publics to be already busy with concerns that were both highly relevant to the data practices we were trying to facilitate, while at the same time overflowing and provoking our framing of the publics we were attempting to engage. Drawing from work in Science and Technology Studies on multiple ways of “doing good” in practice, we propose a reconsideration in design of the publics that we hope to “spark into being,” by pursuing the question of how to design with rather than for publics that are already busy.