Tattoos can tell a lot about a person. They can reveal someone’s religious views, express political opinions, hint at family life, and much more. But if the federal government gets its way, your tattoos could soon be used to put you behind bars.

The National Institute of Standards and Technology recently completed a test of a tattoo image-matching system that could be used by law enforcement to find suspects in a criminal case. The test (named Tatt-E, or Tattoo Recognition Technology Evaluation) attempted to match different images of tattoos gathered by law enforcement agencies by using algorithms created by private companies.

The results weren’t good.

On the first try, the top-performing algorithm was only able to match two images of a tattoo with 67.9 percent accuracy. More troubling is that this algorithm doesn’t even factor in the possibility of “false positives.” Dave Maass, of the civil liberties nonprofit Electronic Frontier Foundation, describes false positives as “when the software says it has matched two tattoos, but the match turns out to be in error.” That means, in all likelihood, that the 67.9 percent accuracy number is actually inflated — which shouldn’t be that surprising. After all, Immigration and Customs Enforcement has already used tattoo recognition as evidence to falsely accuse a Deferred Action for Childhood Arrivals recipient of having gang affiliations and deport him.

The FBI has been sponsoring NIST’s program for the last four years, hoping to one day use this technology in its own investigations. But even if these algorithms could effectively match tattoos at a high rate, there would remain a host of serious civil liberties concerns around the use of these algorithms — from religious liberty to the Fourth Amendment to basic due process.

As federal agencies build out these massive databases, private companies are forking over your data without any reason to suspect you’re guilty of a crime. Earlier this year, Amazon began selling its facial recognition system, known as Rekognition, to local police departments. Now it’s actively pushing ICE to purchase Rekognition as well. So it’s not hard to envision a world where Amazon, or a company such as Facebook, would sell data it has collected about the tattoos of millions of Americans to law enforcement.

The Department of Homeland Security is already developing a massive biometric database called the Homeland Advanced Recognition Technology, which will include facial recognition data, tattoo recognition data, DNA, scar details, and other “physical indicators” on some 500 million people, most of whom won’t be convicted (or even suspected) criminals. Imagine what injustice could occur if such a database is weaponized in conjunction with an ineffective tattoo recognition algorithm.

Because many people in the HART database will inevitably be innocent, such a program would not only raise due process concerns but also worries over religious freedom and free speech. It’s most certainly a violation of the First Amendment for the government to use a massive database to harass individuals who ink their bodies with certain religious or political symbols or slogans. After all, tattoos communicate ideas — so they count as a form of speech. Much of that speech, whether political or religious, is clearly protected by the First Amendment.

It’s not far-fetched, either, to think an administration hostile toward a particular religion (whether that be Christianity, Islam, or Judaism) could use a tattoo database to target members of that religion with surveillance, increased police presence, or even arrest.

In 2016, then-candidate Donald Trump called for the surveillance of American mosques. What’s to stop that same administration from using a comprehensive tattoo database to target folks who may have Arabic words or Islamic symbols tattooed on their bodies?

Or consider an administration like former President Barack Obama’s, one that may want to target Tea Party groups for surveillance. They could abuse such a database to go after anyone with a Gadsden flag proudly tattooed on them.

The prospect is more than frightening.

Even if tattoo-matching algorithms paired tattoos with near certainty, compiling massive databases of tattoos from law-abiding Americans still threatens due process, religious liberty, and free speech. It’s crazy that this has to be said: Your ink shouldn’t be the impetus for your imprisonment.

Dan King is a Young Voices contributor, journalist, and digital communications professional based in Arlington, Va.