(CNN) Lawmakers in Hawaii have introduced legislation that would require internet users to pay a one-time $20 fee to gain access to online pornography. The money collected would be deposited into a fund to help fight human trafficking and the exploitation of children.

The state has three measures up for consideration, including two companion bills in the state's House and Senate

"It doesn't make sense for children to have access to X-rated material on their cell phones," said Hawaii State Sen. Mike Gabbard, who sponsored the Senate bill. He also introduced a similar bill during last year's legislative session.

"By making it harder for people to access these porn sites, we can make prostitution hubs harder to access, which will reduce sex trafficking," Gabbard said in an email to CNN. Gabbard is the father of US Rep. Tulsi Gabbard, a candidate for the 2020 Democratic nomination for president.

Hawaii is the latest state to introduce a version of the Human Trafficking and Child Exploitation Prevention Act , which seeks to restrict access to pornography. An advocacy group called Special Forces of Liberty has been pushing similar tax bills in state legislatures around the country to fund anti-trafficking efforts.

Kathleen Winn, a spokeswoman for the SFL, said the bills were "not putting restrictions on content, but on the access to it." She compared it to similar restrictions on pornography and adult content that were in place when she was growing up in the days before the internet.

"In stores, Playboys and Penthouses were wrapped in brown paper. Those laws are still on the books," Winn said. "And kids can't go to R-rated movies."

Josh Wisch, the executive director of the ACLU of Hawaii, said most electronic devices already come with sufficient ways to block indecent content, should users opt in. He argued "parent-enabled filters" could better protect children from pornographic material than a "one-size-fits-all filter" introduced by government.

Such a filter, if passed, would amount to "an unconstitutional act of state censorship," he said.

Wisch said he worried the filter "would block things it's not meant to block," catching sexual material of an educational or public health nature. Wisch added that individuals seeking legitimate information about sexual identity or sexually transmitted diseases might feel shame in having to identify themselves to the government.

"The First Amendment doesn't come with a $20 asterisk," he said.

Dave Maass, a senior investigative researcher for the Electronic Frontier Foundation, has been monitoring efforts to introduce online porn taxes in multiple states over the past few years. In a 2017 post on EFF's site , Maass wrote that bills requiring a fee to access online porn amounted to "just plain, awful policy."

He said the bills would require manufacturers of internet-connected devices to preinstall filters to block pornography. The filters would be removed once the user paid the $20 fee.

Maass argued such laws would harm consumer choice, forcing people to "purchase a software program they don't necessarily want." And he feared that companies might be compelled to over-censor questionable content for fear of accidentally breaking the law.