Data collection and processing for personalized advertising has become a common practice in the industry. For this reason, regulators have been aiming to empower consumers to exercise more control over their data. Companies that collect and process data for personalized advertising are required to be transparent and among others, provide consumers with technical knowledge about the personalization process. At the same time, they have started offering settings to withdraw consent for processing data for personalization purposes by opting out from personalized advertising. However, such opt-out functions remain mostly unused. Thus, this study investigates first, if technical knowledge about personalization empowers consumers to use such opt-out functions and second, what mechanisms can explain the empowering impact of knowledge. Drawing on Rogers’ (1975) protection motivation theory (PMT) and applying an innovative combination of traditional (online experiment, N = 425, Mage = 48) and computational (online behavior tracking, N = 80, Mage = 48) research methods, the study shows that technical knowledge has no empowering effect on consumers by indirectly lowering opt-out motivation and behavior. The results also demonstrate that perceived severity and response efficacy increase motivation to opt-out, while positive attitude towards personalization and perceived self-efficacy lower it. Being one of the first studies to apply PMT to personalization context and computational methods to measure opt-out, it offers several important societal and theoretical implications regarding consumer empowerment and personalized advertising online.