Technological development and increasing personal data collection and utilization raise the importance of understanding individuals’ privacy behavior. Privacy behavior denotes the willingness to disclose personal data for services utilizing these data. The literature presents various privacy behavior models (PBMs). However, the research is incoherent, with inconsistencies among models. Therefore, the application and subsequent development of PBMs are challenging. Different background theories are used for model construction, and studies have been conducted in distinct application domains. We studied whether the models’ inconsistencies could be explained by these differences. Our in-depth analysis of PBMs was based on a systematic literature review of the most often cited key studies. Our findings indicate that the choice of theories and the application domains do not explain inconsistencies; instead, the models are often of an ad hoc type and constructed in an eclectic way. These results imply the need for more consistent research on privacy behavior.