This paper deals with the ethical aspects of intellectual property infringements and their common acceptance today. The key issue discussed is the influence the ontological quality of an object may have on choices made by a moral agent. The authors argue that there is a correlation between the immateriality of intellectual property and the frequency of theft associated with it. In the first part, the authors offer juridical definitions of immaterial products, intellectual property, etc.. In the second part, some popular arguments for protecting intellectual property are presented, such as those advanced by John Locke and Jean Jacques Rousseau. Third, a concept of self-permissibility is proposed. The paper concludes with a presentation of possible motives for intellectual property infringements, derived (1) from legal regulations (their complexity, their social ignorance etc.), and (2) from sources such as social, historical and moral conditions (the difference in perception of material and immaterial goods is presented among them).