Software piracy has been studied by academics, software firms, law enforcement agents and policy makers for many years. Previous research in software piracy either did not differentiate between unauthorized copying and unauthorized sharing, or focused only on unauthorized copying. We believe the motivating factors behind the two behaviors are quite different because beneficiaries of the behaviors are different. In this paper, we consider unauthorized sharing as a kind of helping behavior and draw on relevant literature to see if the motivations behind unauthorized sharing can be better appreciated from an affective perspective. We tested the affective model of unauthorized sharing based on empirical data obtained from a large-scale survey. We found from the survey that both perceived affordability and perceived convenience could arouse sympathy or annoyance with the unauthorized copier, and their effects were mediated by perceived controllability of the need of unauthorized copying. Our results support the strong effects of affective factors on the moral obligation of unauthorized sharing.