Image by Victor Tangermann

A tech firm that develops genetic forensics tools called Verogen just bought GEDMatch, the company that famously helped police track down the Golden State Killer by letting them access its massive database of customers' DNA profiles.

While the purchase should raise a red flag for the million-plus customers who have sent their DNA to GEDMatch to learn about their ancestry, Verogen told Buzzfeed News that it plans to ask customers to opt in to law enforcement efforts and keep private the information of anyone who says no.

All the same, the acquisition illustrates how little control users have over their own personal information once it leaves their hands.

GEDMatch has helped police solve about 70 additional violent crimes by letting cops compare DNA from a crime scene to its customer database, Buzzfeed News reports.

Verogen CEO Brett Williams told Buzzfeed News that some 200,000 people have already opted in to law enforcement searches. But last month, a Florida detective armed with a warrant was able to access the entirety of GEDMatch's database.

That suggests that opting out may not be the safeguard that it sounds like — either for individual customers, or their relatives who could also be identified through their shared DNA.

"We're not going to force people to opt in," Williams told Buzzfeed News. "If I try that, I know I'll undermine everything."