This is a genuinely interesting ethical question. While our phenotypes (bodies) are separate, our genotypes are very much a shared resource (at least for read a

This is a genuinely interesting ethical question. While our phenotypes (bodies) are separate, our genotypes are very much a shared resource (at least for read access); an extra special case are monozygotic twins, where if you obtain sample from one of them, you just mapped both. Fortunately we don't see applications like "personalized poisons" yet, but it is likely inevitable. If, say, an insurance company denies you some policy because of what they learnt from your relative's DNA, you suffered a concrete harm from that sampling decision.