Online surveys are an efficient and relatively affordable way to collect data. However, there are issues associated with it, including potential fraudulent data due to accidental or deliberate duplicate entries. In this brief we describe a case study of deliberate duplicate entries in an ongoing study of community college students. Students from career technical education (CTE) courses at community colleges across California were invited to participate in a study of persistence in CTE. Shortly after data collection started, we noticed irregularities in survey entries which were subsequently investigated for fraud. Steps were taken to confirm the validity of survey entries and prevent future fraudulent entries. This paper is the first, to our knowledge, to document the process of identifying, rectifying, and reducing the potential for future fraudulent entries in a community college student sample. Our case study can serve as an important lesson for researchers utilizing online survey data collection methods in longitudinal studies.