FWIW - neither Macron nor Scholz are fine with that and based their refusal to take a Russian-controlled PCR test on genetic privacy.

Almost nobody knows that the state does it.

What can they do with the DNA other than checking crimes or mapping genomes?

sell it to insurers to bar people with genetic disorders and predispositions from acquiring life, disability and long-term care insurance.

GINA prohibits discrimination on genotype by health insurance and employers, but those kinds of insurance are left in as loopholes.

(I support the California system, it helps a lot in medical research, I just want the loophole patched.)

source: https://archive.fo/SHfBT

Finding people from remote relatives and medical inferences.

If someone has access to enough nicely distributed DNA samples they can correctly identify you from your DNA even if you are not in any database only based on your family tree.

Varitasium video for reference: https://youtu.be/KT18KJouHWg

This is generally time consuming and done to identify criminals but it is very simple.

> What can they do with the DNA other than checking crimes or mapping genomes?

"Does your husband know that he is not the father?"-type blackmailing for example.

Planting false DNA evidence on people could be a thing.

https://www.reuters.com/world/europe/putin-kept-macron-dista...

> French President Emmanuel Macron refused a Kremlin request that he take a Russian COVID-19 test when he arrived to see President Vladimir Putin this week, to prevent Russia getting hold of Macron's DNA, two sources in Macron's entourage told Reuters.

i can think of so many ways to get the visitor's DNA, like he will naturally lose some hair somewhere, or use the toilet, etc. Maybe the refusal is more a reaction to the mistrust implied in the request to take "their" Test

Getting a data set with the DNA of almost all people in your state is a different beast though.

What can they do to prevent it?

Avoiding giving birth in California seems like an option.