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Doug Johnson's Tech Proof

Filter Follies


We trust Americans to recognize propaganda and misinformation, and to make their own decisions about what they read and believe. We do not believe they need the help of censors to assist them in this task.
~ American Library Associations Library Bill of Rights
Young people have First Amendment rights.
~ American Library Association
To be eligible to receive universal service assistance under subsection (h)(1)(B), an elementary or secondary school (or the school board or other authority with responsibility for administration of that school) shall certify to the Commission that it has--
(A) selected a technology for computers with Internet access to filter or block material deemed to be harmful to minors; and
(B) installed, or will install, and uses or will use, as soon as it obtains computers with Internet access, a technology to filter or block such material.

~ Childhood Internet Protection Act

I have major reservations about filtering devices. Using and relying solely on those imperfect products to limit students access to sites deemed harmful to minors" too often

  1. under-blocks, leaving inappropriate sites accessible.
  2. over-blocks, preventing access to appropriate sites.
  3. blocks sites deemed not politically acceptable (including anti-filter sites) to the filtering authors.
  4. leaves access to inappropriate peer-to-peer networks, chat rooms, or images that cannot be blocked.
  5. allows filters to be easily disabled or worked-around by savvy and ambitious students.
  6. gives teachers, media specialists, administrators, parents, and legislators a false sense of security.

Studies, like those of the Electronic Freedom Foundation in 2003 that examined nearly a million web pages, fueled my concern. The researchers found the following:

  • For every web page blocked as advertised, blocking software blocks one or more web pages inappropriately. Ninety-seven to ninety-nine percent of the web pages blocked were done so using non-standard, discretionary, and potentially illegal criteria beyond what is required by CIPA.
  • Internet blocking software was not able to detect and protect students from access to many of the apparently pornographic sites that appeared in search results related to state-mandated curriculums.

And, as anyone who has worked with children knows, a certain percentage of young people will see any block" as simply a challenge to find a way around. Students can circumvent filters by

  • disabling stand-alone software through simple keyboard combinations.
  • using specialized software such as that available from Peacefire's website.
  • changing a browsers proxy to an unfiltered site.
  • logging into the filtering server using a default administrators password if not disabled.

As clever as we adults might think we are, we usually are at least two steps behind many of the students in our schools.

Want More?

Want to read more about Doug and his thoughts on library media and technology? Visit his Web site or browse his new blog. Got a compliment, a complaint, or just a comment to share? E-mail Doug at [email protected]

Filters, like any other technology, can be used wisely. Our district has taken a number of measures to make sure students and staff can operate in the least restrictive Internet environment possible, to keep students safe, and yet to meet the requirements of CIPA.

1. We based our choice of filters not on cost or convenience, but on features and customizability, and chose the least restrictive settings of the installed filter.
Internet filters have a wide range of restrictiveness. Depending on the product, the products settings, and the ability to override the filter to permit access to individual sites, filters can either block a high percentage of the Internet resources (specific websites, email, chat rooms, etc.) or a relatively small number of sites.

Another study of Internet filtering conducted by the Electronic Freedom Foundation (2002) revealed some other interesting numbers:

  • Schools that implement Internet blocking software with the least restrictive settings will block between .5 percent and 5 percent of search results based on state-mandated curriculum topics.
  • Schools that implement Internet blocking software with the most restrictive settings will block up to 70 percent of search results based on state-mandated curriculum topics.

Another study conducted by the Department of Family Medicine at the University of Michigan Medical School (JAMA, 2002) examined how well seven Internet filters blocked health information for teens at settings from least restrictive to very restrictive. They found that at the least restrictive setting only 1.4 percent of the health information sites were blocked and 87 percent of the pornography sites were blocked. At the most restrictive setting, 24 percent of the health information sites were blocked with still only 91 percent of the pornography sites blocked.

Given the tendency to over-block, we chose to filter in only three of 14 categories:


2. We generously use the override lists in our Internet filter; and we make sure educators can override the filter or have access to a machine that is completely unblocked in each media center so that questionably blocked sites can be reviewed and immediately accessed by staff and students if found to be useful.
Our district media/technology committee decided that any teacher or media specialist may have a site unblocked by simply requesting it -- no questions asked. The technology department was relieved of the responsibility, beyond correctly installing and configuring the filter, for students accessing possibly inappropriate materials; and all school staff members were still required to continue to monitor students while on the Internet as if no filter were present. The technicians now know that it is the responsibility of the teaching staff, not theirs, to see that students do not access inappropriate materials, so there is less tendency to block everything -- just in case."

3. We treat requests for the blocking of specific websites like we would any other material challenge.
We require that when any staff member, parent, or community member requests that a specific Internet site be blocked, the request be treated like any other material challenge in the district. My district, like most, has a reconsideration" policy outlining procedures to follow when someone requests that any material be removed from our schools, whether it is a book from a media center or classroom, a textbook chapter from the curriculum, or a video from the collection. Our policy calls for the person making the request to complete a form specifying what is objectionable about the material. Once completed, a special committee is formed that carefully reviews the material and then makes a recommendation to the school board about the material -- whether to retain it or remove it. The school board then decides the issue, based on the recommendations of the committee. Online resources are given the same rigorous review process before being blocked.


Maintaining both the concept of intellectual freedom and providing a healthy and educational online environment might seem to be a difficult balancing act. But so far, our district seems to have been able to both meet the requirements of CIPA and give staff and students access to the greatest possible range of online resources. As an intellectual freedom advocate, I am monitoring the situation very closely!


Selected resources on the effectiveness of filters written in the past 5 years.
(URLs verified April 2010.)

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