The genetic revolution is well underway, with genetic research and knowledge expanding at an exponential rate. Much of the new genetics research is focused on population groups, and proponents of “population genomics” argue that such studies are necessary since genetic “variation” among human populations holds the most promise for technological innovations that can improve human health and lead to increased understanding of the origin of human populations. Population genomic research thus targets specific groups to discover variation that could lead to knowledge about genetic disorders, possible cures, and the origin and migration patterns of distinctive peoples. Research on genetic differences among groups or populations, however, raises many pressing ethical and legal questions. For example, focus on biological differences of racial and ethnic groups has in the past lead to assumptions about superiority and inferiority between groups, and in practice resulted in stigmatization and discrimination. Consequently, attention on groups should raise legal and moral red flags and compel us to move cautiously in this area. Pragmatically, targeting population groups as the object of study requires the determination of the nature and scope of “population groups” for purposes of genetics research.