We study how diffusing being pivotal affects the willingness to support immoral outcomes. Subjects decide about agreeing to kill mice and receiving money versus objecting to kill mice and foregoing the monetary amount. We investigate an exogenous diffusion of being pivotal imposed by organizational design as well as self-imposed, endogenous diffusion of being pivotal. Regarding exogenous diffusion, we compare two treatments. We keep overall financial incentives and overall payoff consequences identical, yet vary the decision rule: In Baseline subjects decide individually about the life of one mouse. In the Exogenous Diffusion treatment, subjects are organized into groups of eight. Eight mice are killed if at least one subject supports the killing. The fraction of subjects agreeing to kill is significantly higher in Exogenous Diffusion than in Baseline. Moreover, in Exogenous Diffusion, the likelihood to agree to the killing decreases in subjective perceptions of being pivotal. We then show that many subjects actually have a preference to actively create a situation where being pivotal is diffused. In the Endogenous Diffusion treatment, each subject chooses the probability of killing a mouse. The monetary amount a subject receives is proportional to the killing probability. More than 30 percent of subjects opt for intermediate killing probabilities, thereby actively diffusing being pivotal at a proportional reduction of money. Response times and feelings of remorse and bad conscience suggest that it is in particular subjects experiencing moral conflict who prefer diffusing being pivotal. Presumably, this serves as a means to keep a positive self-image while behaving selfishly.