Some consequentialists argue that ordinary individuals are obligated to act in specific, concrete ways to address large-scale harms. For example, they argue that we should each refrain from meat-eating and avoid buying sweatshop-made clothing. The case they advance for such prescriptions can seem intuitive and compelling: by acting in those ways, a person might help prevent serious harms from being produced at little or no personal cost, and so one should act in those ways. But I argue that such reasoning (...) often relies on an overly simplistic assessment of the costs and benefits of those prescriptions, one that misconstrues or neglects important issues. Indeed, a closer look at those costs and benefits reveals just how little we often know about a number of real-world matters that bear on the expected consequences of the prescribed individual actions. Our predicament is one of radical uncertainty: we currently lack a sound basis for concluding that the relevant actions are more likely to do good than to backfire. I distinguish this empirically grounded objection from others, which are not convincing—including one based on the mere conceivability of the actions in question backfiring and another based on the supposition that such actions cannot make a difference in addressing the massive problems at issue. The upshot is that, at least for now, consequentialist arguments for many specific individual actions aimed at addressing large-scale harms are inconclusive. (shrink)