Look, I don't lend my car to strangers, either. But your position is a bit sociopathic.
Just like what these people did. They gave over samples apparently with no written guaranty of how they would be used, and now they're stunned that they have been used for other things.
Yes, they were naive. But they were misled, too. Why are you blaming the victims? If somebody tells you they're doing something to help you, whether that's analyzing your DNA or installing an internet connection or doing your taxes or removing your gallbladder, then they violate your trust, that's wrong. Whether you should have been suspicious of them is a different question.
Universal mistrust doesn't scale. I can't get through a single day without trusting a bunch of strangers not to veer into my lane and kill me, trusting my landlord's employees not to go into my apartment with their maintenance keys and steal my stuff, and trusting my bank not to steal my money. These are calculated risks, but I can't be right all the time. I'd say that trusting researchers from a legit university to do what they said is a pretty reasonable thing to do. But these people got burned.
Yes, we all have to be careful, and try not to get suckered. But traditionally, we don't punish suckers. We punish deceit. I don't know how you can have a sane society otherwise. And I think you'll want more sympathy than you've shown here on that distant future day when you make a mistake and find that you're the sucker.