Internet Filtering Policy


The King County Library System (KCLS) provides access to the Internet on all of its public computers, as well as wirelessly to patron’s personal devices. In compliance with the Children’s Internet Protection Act (CIPA), the KCLS Board of Trustees approved the implementation of Internet filtering software on all of its public computers in August 2003. This policy outlines the way in which the Internet is filtered on KCLS computers.

Statement of Policy

KCLS uses the Internet filtering protocols of the Children’s Internet Protection Act (CIPA), which mandates that any public library using federal funding must filter Internet access to screen for obscenity, child pornography, and in the case of minors, material that is deemed harmful to them.

KCLS provides the following levels of filtered Internet access:

Under 17 Plus

Library cards for all patrons under the age of 17 are set to the default filtering level of "Under 17 Plus." The following filter categories of information are blocked for patrons with the "Under 17 Plus" filter: adult/mature content, child pornography, malicious outbound data/botnets, malicious sources, nudity, pornography, phishing, potentially unwanted software, proxy avoidance and violence/hate/racism.

17 And Up Only

According to CIPA, all adult library patrons must initially have filtered access to the Internet. To that end, library cards for all patrons 17 and older are set to the default filtering level "17 And Up Only." The following filter categories of information are blocked for patrons with the "17 And Up Only" filter: child pornography, malicious outbound data/botnets, malicious sources, phishing, potentially unwanted software, pornography, proxy avoidance.


KCLS also offers an optional and more restrictive filtering level called the "Max Filter." Computers in all children’s areas of KCLS libraries are set to the "Max Filter."

The "Max Filter" blocks all of the same filter categories of information that are blocked for patrons with "Under 17 Plus" filter, as well as the following: abortion, alcohol, auctions, blogs/personal pages, chat/instant messaging, email, extreme, gambling, hacking, illegal drugs, intimate apparel/swimsuit, newsgroups/forums, personals and dating, search engines/portals, sex education, sexual expression, shopping, social networking, tobacco, weapons and web advertisements, web hosting.

It is the responsibility of parents and guardians to monitor and/or restrict the Internet use of their minor children. Patrons may request to increase their filtering level to the "Max Filter" for themselves and their children on all computers.

Filter Off (No Filtering)

If a patron (17 years of age or older) wishes to opt out of filtering, he/she may request this of a KCLS staff member. With valid photo ID, the KCLS staff member may change the patron’s card status to allow unfiltered access.

Illegal Viewing Activity

Regardless of a patron’s filtering level, KCLS does not allow patrons to view any illegal content in the library.


KCLS cannot control access to the resources on the Internet even with filtering software as no Internet filter is 100% effective. Patrons may report sites that they feel should potentially be blocked or unblocked to a KCLS staff member to be evaluated.


Children’s Internet Protection Act (CIPA): The Children’s Internet Protection Act (CIPA) is a federal law enacted by Congress to address concerns about access to offensive content over the Internet on school and library computers. CIPA imposes certain types of requirements on any school or library that receives funding for Internet access or internal connections.

Filter Categories: Groupings of online information to which access can be blocked. Terminology used to describe filter categories are set by the provider(s) of filtering software.

Valid Photo ID: Acceptable examples of photo ID include a driver’s license (current or expired), Washington state ID card, passport, U.S. military ID, or matricula consular (issued by the Mexican government).

Policy Owner(s): Director of Public Services — Operations

Last revised: March 2016

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