The analysis of environmental DNA (eDNA) is a rapidly developing field with great potential and as-yet-undreamed-of uses in conservation and ecology1,2,3. Residual genetic information from environmental samples can reveal species distributions and genotypes4,5,6, among other information about the living elements of ecosystems. However, as with all tools, eDNA techniques can be misused and, in particular, the analysis of human DNA from environmental samples has raised ethical concerns about the information that might be derived from those samples.