Can researchers, interested in novel ways to assess HIV seroprevalence among populations which are otherwise hidden, collect condoms that have been discarded on the ground in a public sex environment and test them for HIV? Researchers, who use other types of abandoned samples, such as discarded syringes, hair or saliva samples, or excess biological samples, confront similar issues. This review evaluates whether such abandoned tissues can be studied based on U.S. Code of Federal Regulations and literature on related issues including: (...) research involving banked tissues, blinded seroprevalence studies, and property claims that individuals might make on the samples.It also addresses broader questions of potential for stigma and risk to individuals and communities. The article concludes that the research should be permitted legally because either it does not involve human subjects, or it satisfies the requirements for waiver of consent; and that the research should also be permitted because the ethical principal of avoiding harm to individuals is fully satisfied based on a careful reading of the lessons of the tissue bank, biological property rights, and blinded seroprevalence study debates, as well as a consideration of other potential harms that might be involved. (shrink)