It is absolutely unacceptable, that's why 2/3 answers to this comment so far use martial metaphors. It violates not the liberty of young men, who have every right to be reckless and volunteer, but integrity of the scientific community.
If the Oxford researchers made trials on Syrian kids in a refugee camp, in exchange for $100, I suppose more people would see a problem here.
If the Oxford researchers made trials on Syrian kids in a refugee camp, in exchange for $100, I suppose more people would see a problem here.