OLYMPIA, Wash. — Public libraries’ refusal to disable content-blocking Internet filters for adult patrons does not run afoul of the state constitution, the Washington state Supreme Court ruled yesterday.

In a 6-3 ruling, the majority said libraries have discretion about which Internet content to allow, just as they decide which magazines and books to offer.

“A public library can decide that it will not include pornography and other adult materials in its collection in accord with its mission and policies and, as explained, no unconstitutionality necessarily results,” Chief Justice Barbara Madsen wrote for the majority in Bradburn v. North Central Regional Library District. “It can make the same choices about Internet access.”

Justices Susan Owens, Charles Johnson, Mary Fairhurst and Gerry Alexander signed on in agreement.

Justice James Johnson wrote a separate opinion, agreeing with the majority conclusion but saying the focus of the reasoning should be on scarcity of resources that libraries deal with, which in turn allows them to filter materials they obtain for their collections.

The majority said libraries, while not completely removing Internet filters, can provide access to individual Web sites containing constitutionally protected speech if requested by an adult.

The majority cited heavily from the U.S. Supreme Court’s 2003 ruling in United States v. American Library Association, which upheld the 2000 Children’s Internet Protection Act. That act requires public libraries to install Internet filters in order to receive federal money.

Four justices in that 6-3 majority said CIPA did not violate the First Amendment, and two others said it was allowable as long as libraries disable the filters for adult patrons who ask.

Citing that fracture in the U.S. Supreme Court ruling, Washington state Supreme Court Justice Tom Chambers said in his dissent yesterday that under the First Amendment, “the library’s filtering policy is at best doubtful and, I predict, will be struck down.”

Chambers, joined by Justices Richard Sanders and Debra Stephens, argued that the majority’s ruling in the Washington state case restricts constitutionally protected speech. Chambers wrote that censoring material on the Internet is not the same as declining to purchase a particular book.

“It is more like refusing to circulate a book that is in the collection based on its content,” he wrote.

The case was sparked by a lawsuit filed by the American Civil Liberties Union of Washington in 2006 against the five-county North Central Regional Library District in Eastern Washington.

The library district, which receives federal money, has filters that block pornography along with content about computer hacking, gambling and personal ads on Craigslist, among other topics.

The U.S. District Court in Spokane asked the state Supreme Court to review the case.

Attorney Duncan Manville, representing the ACLU, said the legal action didn’t challenge the library district’s use of an Internet filter, only the policy of refusing to disable it at the request of adult library patrons.

He also noted that pages the library deems harmful to children — such as gambling sites and others mentioned in its policy — still won’t be unblocked for adults under yesterday’s ruling.

“There’s no dispute in this case that there is a bunch of constitutionally protected speech being blocked,” he said.

The case will now go back to federal court, to be decided under the guidelines determined by the high court.

Dean Marney, director of the library district based in Wenatchee, called the ruling “an affirmation for libraries, common sense, civility, and the appropriate use of public funds.”

The district has 28 branch libraries in Chelan, Douglas, Ferry, Grant and Okanogan counties.

The ACLU represented three library users and the pro-gun Second Amendment Foundation, arguing the district should be ordered to provide unblocked access to the Internet when adults request it.

The plaintiffs include a Ferry County woman who wanted to do research on tobacco use by youth; a professional photographer blocked from using YouTube and from researching art galleries and health issues; and an Okanogan man unable to access his blog, as well as information relating to gun use by hunters.

The Bellevue-based Second Amendment Foundation contends the library district blocked online access to Women & Guns, a magazine it sponsors covering topics such as self-defense and recreational shooting.

Chambers wrote that the entire filter should be removed if requested by an adult patron, because the state “has no interest in protecting adults from constitutionally protected materials on the Internet.”

“Concerns that a child might see something unfortunate on the screen must be dealt with in a less draconian manner,” he wrote.