Do you ever think about the DNA you throw away? There’s actually a surprising amount of it. Stray hairs, discarded coffee cups, gum, leftovers from restaurant meals, cigarette butts, straws, Band-Aids. You might not think much about what happens to your discarded DNA, but some people do. And they’re putting it to surprising, and sometimes unsettling, use.

One interesting use of discarded DNA is to shame people for littering. As this Science Alert article reports, that’s the idea behind an anti-littering campaign in Hong Kong. The campaign is called Face of Litter?a fitting name, since it literally uses the DNA on trash to create an image of the offender and “’put a face’ to the anonymous crime of littering.”

The company who created the advertising campaign says they got permission from the DNA donors. But people who are putting discarded DNA to other uses aren’t necessarily seeking permission from its unwitting providers. And that raises some interesting questions about where, and how, your bio-debris could be used.

Take the example of New York artist Heather Dewey-Hagborg. As this CNN video shows, she’s the creator of a project called Stranger Visions. Using discarded items she finds in public places, Dewey-Hagborg “takes the sample to a community biotechnology lab,” extracts the DNA, and creates 3D-printed portraits of the strangers who chewed that gum or drank from that coffee cup.

The technology isn’t advanced enough to create a perfect portrait. As the artist told CNN, “it’s important to understand that these portraits are a general likeness. They’re not exact reconstructions.” The same goes for the sketches created by the anti-litter campaign in Hong Kong.

Still, the idea of using someone’s discarded DNA to create public images of them, no matter how imperfect, raises some very interesting questions about privacy. Do you still own your DNA even after you’ve discarded it?

In Canada and the US, the law has yet to catch up with technology. Either the issue hasn’t been addressed or, where it has, the law can vary widely from one jurisdiction to another. In the UK, however, it’s been illegal since 2006 for “private citizens to sequence another person’s DNA without permission,” as the Boston Globe notes.

It’s a fine line, the question of whether you have any rights to something you threw away. But when it comes to DNA, the answer should be a resounding yes?for the simple reason that, unlike other objects, your DNA continues to carry unique and highly personal information about you. Everything from your ancestry to your odds of getting certain diseases. That connection, and the data it carries, doesn’t end simply because you’re no longer carrying a particular piece of DNA on you.

Compare it to the personal information on, say, a driver’s license, or a passport. If you lose or discard it, it’s simple for someone to access the data on it. They don’t need a DNA lab for that. But it would almost certainly be illegal for them to use that information in any way, especially things like putting it on public display. Given the immense and very personal details buried in your DNA, any unauthorized use of it should be banned.

That doesn’t mean someone shouldn’t be able to build an eclectic art installation of discarded gum if that’s what floats their boat. But it does mean that, outside of legitimate uses like law enforcement, no one should be able to dismantle your DNA without your permission.

So next time you’re about to toss that piece of gum or half-eaten bagel away in public, think again. Your DNA trash could be someone else’s treasure.

S.D. Livingston is the author and creator of the Madeline M. Mystery Series for kids, as well as several books for older readers. Visit her website for information on her writing.