Maybe an agency or organization building a DNA database. Or maybe they're looking for a specific criminal using familial DNA, similar to how the alleged Golden State Killer was located:
Another contemporary example was the CIA staging a "vaccination campaign" in Pakistan. They were pushing vaccinations, and then harvesting the DNA to try to track individuals related to Bin Laden.
Which created a horrible atmosphere for people actually giving vaccinations, and caused and causes a lot of people to go unvaccinated.
A real blowback is going to be when we realize that Western and middle-class anti-vax sentiment caused by Wakefield and various crackpot websites is going to collide through relatives and immigration with South Asian anti-vax sentiment caused by CIA and military operations masquerading as NGO vaccination programs, and result in a vicious circle of vaccination fears.
https://www.nytimes.com/2018/04/27/us/golden-state-killer-ca...