When I learned about a concerted campaign against Australian vaccination critics, I decided to intervene in the debate. As a result, some proponents of vaccination turned on me, making abusive comments and complaining to university officials. At several points in this experience, I had to make choices about how to intervene or respond. STS perspectives offered valuable insights for understanding the dynamics of the controversy but provided little guidance for making decisions. Some reasons are offered for why STS lacks tools for guiding practical action in such situations.