Obtaining human genetic samples is vital for many biobank research purposes, yet, the ethics of obtainment seems to many fraught with difficulties. One key issue is consent: it is by many considered ethically vital that consent must be fully informed (at least ideally speaking) in order to be legitimate. In this paper, we argue for a more liberal approach to consent: a donor need not know all the specifics of future uses of the sample. We argue that blanket consent is ethically defensible, and that this is buttressed by considerations of (justified) trust-relations. Given robust institutional oversight, blanket consent is a permissible form of consent in the bio-banking context.