Oh wow, read this. Excerpt, emphasis mine:
“Buried in the “Informed Consent” section, which is incorporated into the Terms of Service, Ancestry.com warns customers, “it is possible that information about you or a genetic relative could be revealed, such as that you or a relative are carriers of a particular disease. That information could be used by insurers to deny you insurance coverage, by law enforcement agencies to identify you or your relatives, and in some places, the data could be used by employers to deny employment.”
This is a massive red flag. The data “you or a genetic relative” give to AncestryDNA could be used against “you or a genetic relative” by employers, insurers, and law enforcement.
For example, a young woman named Theresa Morelli applied for individual disability insurance, consented to release of her medical records through the Medical Information Bureau (a credit reporting agency for medical history), and was approved for coverage. One month later, Ms. Morelli’s coverage was cancelled and premiums refunded when the insurer learned her father had Huntington’s disease, a genetic illness.“