The use of signed consent forms is mandated by most human research ethics committees and social science ethics codes. In this article we argue that the use of signed consent forms in criminological research provides protection for researchers and ethics committees by providing documentation that informed consent has been obtained, but poses a threat to potential research participants, especially offenders. Consent forms constitute a record of participation in a research project, providing the potential for research documentation to be subpoenaed. This is a threat to the offender's future wellbeing in research where offenders are asked to report on illegal activities. Further, there is a general reluctance among offenders to sign consent forms, creating a barrier to participating in research and potentially affecting response rates and representativeness of samples. Concerns over confidentiality may result in limited disclosure and self-protecting responses. We recommend the development of alternative methods of obtaining informed consent that provide greater protection for research participants.