The principle of 'Scarcity' refers to the human tendency to value and desire something more when it is perceived as rare or dwindling in availability. In the context of social engineering, an attacker may use this principle to create a sense of urgency and prompt immediate decision-making, potentially leading to the victim taking an action they might not have taken under normal circumstances. This may manifest as limited time offers, exclusive access, or in this case, a limited number of available licenses which could lead to hasty purchases without proper verification.