The paper discusses the insights gained from the supervision of software engineering students who are writing programs that detect “dark patterns” on online interfaces. Hence, the supervisors pursue educational goals while introducing students to the field of computer ethics. The detection programs analyze the HTML code of sales portals. The commandments of computer ethics prohibit the causing of harm and require a consideration of the social consequences of the system being designed. Deceptive patterns are harmful to consumers, not to sellers. We hold that the loss of trust in unfair sellers is a more serious problem than just the use of pre-checked boxes. Information technologies become untrustworthy. User consent becomes inefficient because users are burdened with analyzing risks on webpages.