Bills against book bans are gaining traction in state legislatures around the country — and with them have come worries about the potentially negative impact on libraries themselves.

The number of banned books across the country saw an almost two-thirds increase in 2023 from the previous year, to more than 4,200 titles, according to a new report from the American Library Association. The free speech advocacy group PEN America found that last school year, about 30% of the book titles being challenged in schools included characters of color or discussed race and racism, while another 30% presented LGBTQ characters or themes. In addition, almost half the banned books featured themes or instances of violence or physical abuse, and a third contained writing on sexual experiences between characters.

The rise in book bans has prompted lawmakers to push back with bills in New York, New Jersey, Pennsylvania, Colorado, Oregon, Washington and New Mexico. They follow Illinois and California, where such legislation has been signed into law.

Experts are raising concerns, however, as some of the legislation would fine school districts or withhold library funding if their provisions are not followed, such as in Illinois and California. The enforcement measures could especially be a threat to public schools and libraries that are underfunded and understaffed, they say.

“It always is a concern when you put funding on the line for any reason,” said Deborah Caldwell-Stone, director of the American Library Association’s Office for Intellectual Freedom.

“We would not want to see bills that are overly prescriptive that make it difficult for smaller communities or rural communities to receive their funding.”

She added, “Our big concern is not creating a system that would make it so onerous to comply with the bill that it makes it difficult for libraries with fewer resources.”

Budgetary constraints also can give rise to circumstances that could be misread as violations of state laws, experts say. For example, titles may be removed or go missing from the shelves of schools or public libraries when the books are damaged or lost or there’s no money in the budget to purchase them. Personnel shortages also can prevent libraries from staffing panels that review books or instructional materials for approval or disapproval. Some experts argued that such problems could be unfairly weaponized against schools or public libraries, which have experienced increased criticism and scrutiny as part of the growing movement to ban books.

Illinois’ new law requires that state libraries adopt the American Library Association’s long-standing Library Bill of Rights, which says that reading materials cannot be banned, removed or restricted due to “partisan or doctrinal disapproval,” or, alternatively, a similar statement prohibiting the banning of books. If public libraries don’t adopt such guidelines, they become ineligible for state grant money, which makes up a substantial part of their budgets.

When asked about the concerns over the law, Illinois state Sen. Laura Murphy, a Democrat who co-sponsored the measure, said in a statement to NBC News that by adding the threat to funding to the legislation, lawmakers were “intentional in establishing a mechanism to hold libraries accountable and sending a clear message that there would be a recourse for those who seek to ban books.”

She added that the law’s enforcement gave it more of a backbone and was a way to “further demonstrate our support for librarians” who back efforts to keep an inclusive range of book titles available.

Emily Knox, an associate professor in the School of Information Sciences at the University of Illinois at Urbana-Champaign, said that she believes connecting funding to Illinois’ bill is necessary for its effectiveness.

“That’s what gives the bill any teeth at all,” she said. “Libraries and schools need more money, but because funding is so precious to public institutions, you don’t want to do things that jeopardize the possibility of getting funding from a source like the state. So it does make a big difference.”

Knox said claims that the funding could be weaponized against libraries in the state if they are targeted for not having certain titles on the shelf are inaccurate based on the wording of the legislation.

“The bill says that [libraries] have to support the ALA Bill of Rights and have a process in place for reconsidering books. It doesn’t say what the outcome of that process is,” she said.

Since the Illinois bill just mandates the policy to taken up by libraries, rather than specifying what specific books should or shouldn’t be on the shelves, libraries can’t be targeted for lacking book titles, Knox said.

And the law is already proving effective, she said, noting that the director of the public library in Metropolis, Illinois, was dismissed last month in part for challenging the library board’s decision to conform to the state’s law and adopt the ALA Bill of Rights, which the board said was necessary to do in order to receive state grants that the library needs.

California’s law focuses on penalizing school districts if books are determined to have been rejected from their library shelves for discriminatory reasons, which would result in financial penalties from the state Education Department. Gov. Gavin Newsom said the law aims to protect access to books which “reflect the diverse experiences and perspectives of Californians.”

Caldwell-Stone warned that in a national environment in which librarians face growing criticism about the types of books they provide, laws against book bans must consider the potential pitfalls and burdens on library staff.

Some state lawmakers have reconsidered the inclusion of financial penalties for libraries in their bills amid the fears of unintended consequences. In New Jersey, legislators dropped that language from their bill after librarians expressed concerns.

State Sen. Andrew Zwicker, a Democrat who sponsored the bill, said that he grew concerned about the potential impact of such penalties after hearing from several librarians about the criticism and scrutiny they’ve received amid the increasing challenges to various book titles.

Washington and Oregon have advanced legislation against book bans that focus on school districts, but neither includes fines like California’s law. Washington’s bill is waiting for Gov. Jay Inslee’s expected signature, and Oregon’s measure has been passed by the state Senate.

Both bills would prohibit the exclusion of instructional materials for including information on the role or contributions of individuals and groups protected from discrimination based on race, religion, sexual orientation and other characteristics.

Washington state Rep. Monica Stonier and Oregon state Sen. Lew Frederick, Democrats who introduced their respective bills, explained that their measures would simply enact vetting processes for books that are already being used in school districts across the state, unifying those district protocols while adding anti-discriminatory protections.

Lawmakers in support of the laws in Washington and Oregon say that they plan to see how California’s enforcement provisions play out before considering adding a fine to their bills.

“We already have a way to do this, there doesn’t seem to be a need to set up another one,” Frederick said. “I think this is a simple approach because it just says you can’t discriminate.”