AbstractThe most important ethical question regarding PTs is the voluntariness of changes they bring about. Coercive technologies control its users by application of direct force or credible threat. Manipulative technologies control their users by influencing them in ways of which the users are not aware and cannot control. As a result, both violate the voluntariness condition of the standard definition of PTs. Any voluntariness assessment needs to consider whether there are external controlling influences and whether the user acts intentionally.