With just a single warrant, a Florida detective obtained access to the DNA profiles of more than a million people — and experts say the case sets a dangerous precedent.

Ancestry.com and 23andMe are the largest consumer DNA sites, holding genetic data on 15 million and 10 million people, respectively. However, they aren’t the only DNA sites out there — a smaller service, GEDmatch, currently has about 1.3 million users, each of whom is able to search the site’s entire database.

In May, GEDmatch changed its policies so that law enforcement officials could only search the profiles of people who opted into such searches, which GEDmatch co-founder Curtis Rogers recently told The New York Times about 185,000 users have done.

Prior to the change, police famously used GEDMatch to crack the case of the Golden State Killer, resulting in the arrest of a suspect in April 2018. Detective Michael Fields had also used the database to solve a case prior to the May change and was hopeful it might help with a new one he was investigating in July.

To that end, Fields decided to ask a Florida judge to grant him a warrant that would override the new policy, allowing him to search GEDmatch’s entire database, including users who hadn’t opted in — and Judge Patricia Strowbridge did just that, the detective announced at a recent police convention, according to the NYT.

Legal experts told the NYT that this appears to be the first time a judge has approved a DNA website warrant this broad, with New York University law professor Erin Murphy calling it “a huge game-changer.”

“The company made a decision to keep law enforcement out, and that’s been overridden by a court,” Murphy told the newspaper. “It’s a signal that no genetic information can be safe.”

Again, GEDmatch is far from the biggest consumer DNA site. However, by granting Fields his warrant — which, he told the NYT, has resulted in some new leads for his case but no arrests — the judge may have set a precedent that makes the DNA of tens of millions of people searchable by law enforcement, whether they agree to the searches or not.

“I have no question in my mind that if the public isn’t outraged by this, [law enforcement agencies] will go to the mother lode: the 15-million-person Ancestry database,” Murphy told the NYT. “Why play in the peanuts when you can go to the big show?”

And that’s a tricky situation.

On the one hand, if accessing the databases gets killers off the street, that’s obviously a good thing. But the information in DNA databases isn’t always accurate, which means its use by law enforcement could result in wrongful arrests or convictions.

Then there are the privacy issues to consider. If there’s evidence that the data of a single user on a DNA site could help solve a crime, it might make sense for a judge to grant a warrant for that data. But a warrant giving law enforcement officials access to all of the data on a site? That could be a privacy nightmare.

READ MORE: Your DNA Profile is Private? A Florida Judge Just Said Otherwise [The New York Times]

More on DNA searches: A Genealogy Website Led to a Suspected Killer’s Arrest. Here’s What We Know.