There's a bill out there that might initially irk people across the country, but could be a boon for curbing what President Donald Trump once called an "epidemic." It's called the Human Trafficking Prevention Act and it proposes a tax on porn – and lawmakers from approximately a dozen states are mulling it over.

If passed, consumers would have to pay a single $20 tax to access pornography on any new computer or phone. States like South Carolina, Georgia and Texas are looking into variants of the bill, while North Dakota and Wyoming, for instance, have squashed it.

Advocates contend porn is a public health issue. In their minds, taxing it could help curb sex trafficking, for example. According to the act's website,"The temptation to hire a prostitute to deal with one’s emotional challenges will be reduced tremendously by this act."

"What we know about pornography is that it's addictive. It actually affects the brain," Kathleen Winn of the Arizona Anti-Trafficking Network told 3TV/CBS 5. "Like any drug, like an addiction, you need more and more and more of it to get the same reaction from it as the first time you saw it. So yes, I absolutely believe pornography is contributing to the growing criminal enterprise of sex trafficking."

Trump has said he would fight human trafficking, which he called an "epidemic." In the U.S. alone, the National Human Trafficking Hotline learned of 22,191 sex trafficking cases since 2007, according to Polaris, a nonprofit that works to combat human trafficking. The International Labor Organization approximates 4.5 million people are stuck in "forced sexual exploitation" across the world.

The money from the proposed tax would go to organizations opposing human trafficking, sexual assault and domestic violence, reports 3TV/CBS 5. Those in favor of the bill want to push it federally soon.

But is the act constitutional?

Not according to Russ Richelsoph, an Arizona attorney. "While I'm not advocating pornography, it is a form of speech. It is protected by the First Amendment, and it is a problem if they're trying to create a tax to prevent people from engaging in that form of speech," he told 3TV/CBS 5.

While pornography has historically been taboo, it's not always easy to define. As the late Supreme Court Justice Potter Stewart once famously said: "I know it when I see it."