This document discusses "dark patterns", which are user interface design patterns that are intentionally manipulative. Dark patterns use psychology and ethnography to emotionally manipulate users. Examples of dark patterns discussed include roach motels, which make it easy to join but hard to leave; forced continuity, where canceling a free trial is difficult; hidden costs that are only revealed at checkout; and trick questions that mislead users. While dark patterns can increase metrics like clicks and sales, the document questions whether they should be used, as they prioritize persuasion over empathy and putting the user first.