[asperous]

No singular person, it's more the value of having a large database. You visit a coffee shop, a stalker collects your dna from a fingerprint and uses the a leaked or sold database from 23andme to tie it to your identity or home address, etc.

Interestingly this also works if a direct relative has used it as well.

[dullcrisp]

Couldn’t they find you on facebook instead of sequencing your genome?

[Larrikin]

Does anyone under 40 have a non locked down or an undeleted Facebook account?

[lentil_soup]

If a stalker already followed you into a coffee shop surely they have your name and address