During a recent hearing, Dr. Steven Quay explained how the process typically works. What people receive in the mail and use to swab their DNA is then sent off to companies that in many cases are based in China.

"So if you go on the internet and want to do a DNA test for almost anything on the internet as a consumer – and you don't even need a doctor to sign – and you do a scrape, the specimen will very often go to a laboratory here," Dr. Quay stated.

"But then it gets shipped to BGI, which bought more Illumina sequencing machines than any other place in the world."

Illumina sequencing machines, by the way, are used to process microarrays. These are what supposedly determine a person's lineage going back to the early days of the family tree.

"And so they will do the sequence there and they'll send it back to the company, but guess what? They'll keep a copy," Dr. Quay further warned.

"And that's what he's talking about. So every time an American – not always, but many times – you will do what you think is a U.S. address and then it gets shipped to BGI."