The Problem of Collective Harm: A Threshold Solution
https://ejpe.org/journal/article/view/798
“Many harms are collective: they are due to several individual actions that are as such harmless. At least in some cases, it seems impermissible to contribute to such harms, even if individual agents do not make a difference. The Problem of Collective Harm is the challenge of explaining why. I argue that, if the action is to be [moral], the probability of making a difference to harm must be small enough.”