Filters and Filtering

The use of Internet filters to block constitutionally protected speech, including content on social networking and gaming sites, compromises First Amendment freedoms and the core values of librarianship. Internet safety for children and adults is best addressed through educational programs that teach people how to find and evaluate information.

Research demonstrates that filters consistently both over- and underblock the content they claim to filter. Filters often block adults and minors from accessing a wide range of constitutionally protected speech. Content filters are unreliable because computer code and algorithms are still unable to adequately interpret, assess, and categorize the complexities of human communication, whether expressed in text or in image.

"The negative effects of content filters on Internet access in public libraries and schools are demonstrable and documented. Consequently, consistent with previous resolutions, the American Library Association cannot recommend filtering. However, the ALA recognizes that local libraries and schools are governed by local decision makers and local considerations and often must rely on federal or state funding for computers and internet access. Because adults and, to a lesser degree minors, have First Amendment rights, libraries and schools that choose to use content filters should implement policies and procedures that mitigate the negative effects of filtering to the greatest extent possible. The process should encourage and allow users to ask for filtered websites and content to be unblocked, with minimal delay and due respect for user privacy."

—  Internet Filtering: An Interpretation of the Library Bill of Rights

ALA Statements and Policies on Internet Filtering and Access to Online Information

Internet Filtering:  An Interpretation of the Library Bill of Rights (2015)  

Minors and Online Activity: An Interpretation of the Library Bill of Rights (2019)
The digital environment offers opportunities for accessing, creating, and sharing information. The rights of minors to retrieve, interact with, and create information posted on the Internet in schools and libraries are extensions of their First Amendment rights.

Access to Digital Resources and Services: An Interpretation of the Library Bill of Rights (2019)
Digital resources and services allow libraries to significantly expand the scope of information available to users. Like all resources and services provided by the library, provision of access to digital resources and services should follow the principles outlined in the Library Bill of Rights to ensure equitable access regardless of content or platform.

Resolution on Opposition to Federally Mandated Internet Filtering (2001)

Statement on Library Use of Filtering Software (1997)
On June 26, 1997, the United States Supreme Court in Reno v. American Civil Liberties Union, 521 U.S. 844 (1997), issued a sweeping reaffirmation of core First Amendment principles and held that communications over the Internet deserve the highest level of Constitutional protection.

International Statements on the Internet and Access to Online Information

Internet Manifesto (2014)
International Federation of Libraries / FAIFE (Committee on Freedom of Access to Information and Freedom of Expression)

ALA Publications and Toolkits

Guidelines to Minimize the Negative Effects of Internet Content Filters on Intellectual Freedom (2017)
ALA Intellectual Freedom Committee
Guidelines to provide public and school libraries with information about how to select, configure, manage, and assess content filters to minimize the negative effects on free inquiry and the privacy of library users.

Intellectual Freedom Manual (2021)
Edited by Martin Garnar and Trina Magi with ALA Office for Intellectual Freedom
The 10th edition manual is an indispensable resource for day-to-day guidance on maintaining free and equal access to information for all people with a chapter titled "Censorship, Challenged Resources, and Internet Filtering".

Fencing Out Knowledge: Impacts of the Children's Internet Protection Act 10 Years Later (2014)
By Kristen R. Batch with ALA Office for Information Technology Policy and ALA Office for Intellectual Freedom

Filtering and the First Amendment (2013)
By Deborah Caldwell Stone published in American Libraries

Minors' First Amendment Rights: CIPA and School Libraries (2010)
By Theresa Chmara published in AASL's Knowledge Quest

Internet Filtering (2010)
By Sarah Houghton published in Library Technology Reports

Why Filters Won't Protect Children or Adults (2004)
By Nancy Kranich published in Library Administration & Management

Lester Asheim in Cyberspace: A Tribute to Sound Reasoning (2002)
By June Pinnell-Stevens published in American Libraries

Articles and White Papers on Filtering

Do You See What I See? Capabilities and Limits of Automated Multimedia Content Analysis (2021)
Center for Democracy and Technology

Internet Filtering and Adolescent Exposure to Online Sexual Material (2018)
by Andrew K. Przybylski and Victoria Nash, published in Cyberpsychology, Behavior, and Social Networking

The Inconsistent Work of Web Filters: Mapping Information Access in Alabama Public Schools and Libraries (2017)
By Chris Petersen, Shannon M. Oltmann, and Emily J.M. Knox, published in the International Journal of Communication

Internet Filtering Technology and Aversive Online Experiences in Adolescents (2017)
By Andrew K. Przybylski and Victoria Nash published in the Journal of Pediatrics
"Contrary to our hypotheses, policy, and industry advice regarding the assumed benefits of filtering we found convincing evidence that Internet filters were not effective at shielding early adolescents from aversive online experiences."

Access Denied: How Internet Filtering in Schools Harms Public Education (February 2013)
by the ACLU of Rhode Island

Children's Internet Protection Act (CIPA) and E-rate

Children's Internet Protection Act
Information provided by the ALA Advocacy and Public Policy Office.

United States v. American Library Association, 539 U.S. 194 (2003)
Legal Briefs filed in United States v. American Library Association (CIPA Before the Supreme Court)

E-rate and Universal Service
Information provided by the ALA Advocacy and Public Policy Office.

FCC Report and Order 11-125, August 21, 2011 (report and regulations implementing CIPA)

CIPA: A Brief FAQ on Public Library Compliance (2012)
By Bob Bocher with the Wisconsin Department of Public Instruction

Library Internet Filtering Update (2012)
By Theresa Chmara with Freedom to Read Foundation

Why Recent Court Decisions Don’t Change the Rules on Filtering (2012)
By Theresa Chmara published in American Libraries

State Laws Relating to Filtering, Blocking, and Usage Policies in Schools and Libraries (2016)
National Conference of State Legislatures (updated periodically)

Filtering Software 

(Note: The American Library Association does not endorse or recommend any internet filtering software. These resources are provided for those interested in learning more about the operation and effectiveness of filtering software.)

Deloitte Risk Services, Synthesis Report: Test and benchmark of products and services to voluntarily filter Internet content for children between 6 and 16 years,  2008 (Prepared for the European Union's “Safer Internet plus Programme”)

Internet Filters: A Public Policy Report (2006)
By Heins, M., Cho, C. and Feldman, A.,
Brennan Center for Justice at the NYU School of Law, Free Expression Policy Project

Internet Filtering Software Tests: Barracuda, CyberPatrol, FilterGate, & WebSense(2008)
Sarah Houghton and the San José Public Library

The Effectiveness of Internet Content Filters (2008)
Philip B. Stark
I/S: A Journal of Law and Policy for the Information Society

Internet filtering companies with religious affiliations in the context of Indiana public libraries (2007)
By R. Radom published in LIBRES: Library and Information Science Research Electronic Journal

Filtering Software: The Religious Connection (2002)
By Nancy Willard
also see the summary and links to individual reports.

Parental controls: advice for parents, researchers, and industry (2016)
By Bieke Zaman and Marije Nouwen


Filtering: The Man in the Middle. Chicago, IL: American Libraries Live.
Featured Speakers: Doug Archer, Bob Bocher, Deborah Caldwell-Stone, Jamie LaRue, Michael Robinson
Recorded: September 15, 2016

Championing Internet Access for Students on Banned Websites Awareness Day . Chicago, IL: American Association of School Librarians (AASL)
Featured Speakers: Doug Archer, Bob Bocher, Deborah Caldwell-Stone, Jamie LaRue, Michael Robinson
Recorded: September 2015

How to be a Ninja Warrior Filter Fighter! Chicago, IL: American Association of School Librarians (AASL)
Featured Speakers: Gwyneth Jones
Recorded: September 2014

Additional Resources on Internet Filtering, Digital Rights, and Online Safety

American Library Association/Association for Library Service to Children,  Notable Children's Digital Media

American Civil Liberties Union
"The ACLU believes in an uncensored Internet, a vast free-speech zone deserving at least as much First Amendment protection as that afforded to traditional media such as books, newspapers, and magazines."

" is a Silicon Valley, Calif.-based nonprofit organization dedicated to educating users of connected technology about safety, privacy, and security. Here you’ll find research-based safety tips, parents’ guidebooks, advice, news, and commentary on all aspects of tech use and policy."

Electronic Frontier Foundation
"EFF defends the Internet as a platform for free speech, and believes that when you go online, your rights should come with you."

NetSmartz for Parents and NetSmartz for Kids National Center for Missing & Exploited Children, 2001-2015

Open Net Initiative (2014)
"Internet censorship and surveillance are growing global phenomena. ONI’s mission is to identify and document Internet filtering and surveillance, and to promote and inform wider public dialogues about such practices".

" was created in August 1996 to represent the interests of people under 18 in the debate over freedom of speech on the Internet." Digital Citizenship, Online Safety, and Civility

Wired Safety website

Assistance and Consultation

The staff of the Office for Intellectual Freedom is available to answer questions or provide assistance to librarians, trustees, educators and the public about internet filtering. Areas of assistance include policy development, First Amendment issues, and professional ethics. Inquiries can be directed via email to or via phone at 800-545-2433, extension 4220.

Updated May 2017