Internet Filtering
by Rich Miller
May 28, 2008
I wanted to take some time to
talk about the District's Internet website content filtering -
which is different from our email filtering. I'm sure most of you
are familiar with the Information Systems yellow warning screen
that was new this year (and hopefully friendlier), here is some
background:
Content Filtering Overview
From a legal point of view, we are required to filter our Internet
content in a best effort to prevent objectionable material from
reaching children under the Children's Internet Protection Act
(CIPA). In order to receive federal funding assistance for Internet
access and internal connections, the District must be CIPA
compliant. Regardless of the legal ramifications, it is also the
District's desire to protect children from offensive content. An
added component is enforcement of the District's acceptable use
policy for all staff.
Category Filtering
As a starting point, we subscribe to a service that categorizes
websites and then blocks those categories we have chosen (such as
violent, adult, criminal, etc.). We allow websites that are
uncategorized or unknown but that may change. The service
constantly updates its database which may result in a site you
could reach one day being blocked the next - it may very well be
that no one in IS made a change to the filter.
Custom Filter List
We tailor the filter for our use by maintaining a list of sites or
keywords that we either choose to permit or block. This is not an
exact science, but we do our best. At times it is entertaining, at
times frustrating, and, quite possibly, it could be someone's
full-time job.
Exceptions
If there is a site you need to use to educate your students, let us
know. I saw "puzzle-maker.com" get stopped at the firewall today,
and I added it to our permitted list. There is no effort or desire
to prevent you from accessing sites you need to do your job. Submit
an Information Systems Work Order and select the category
"Website-Allow" and we'll evaluate your request.
Google Images
While Google's image search is a powerful tool, it is also a major
source of unwanted content. The main culprit is the ability for a
user to turn the default safe search filtering off. With this
setting, even the most innocent searches can become objectionable.
If you encounter the yellow warning screen during a search make
sure "safe search" is on. Even with the safe search on, be aware
that some objectionable images may still come through.
Video
Ah video, the true double-edged sword. There is no way we can
successfully filter video for content, hence youtube is blocked.
Alternatives are United Streaming, TeacherTube (which I have just
now been experimenting with), and most news organizations. We are
evaluating other collaborations and avenues to provide more
educational video resources.
Proxy Sites
A proxy site is a site that allows a user to access blocked content
by masquerading as something else. I can personally attest to the
fact that much Internet search time is spent trying to find proxies
that we have not yet blocked. The sole purpose of these sites is to
bypass the protections we have put in place, and, as a result, use
of a proxy site will be viewed as a violation of the acceptable use
policy.
Future
We have purchased and are experimenting with a replacement firewall
that will give us more flexibility in our filtering. Specifically,
we may implement different filtering schemes based on the end user
- perhaps tightening our filtering for students, but loosening some
of the restrictions for staff.
To summarize, filtering is necessary and receives much thought and
attention in Information Systems. Philosophically we will continue
to strive to err on the conservative side, which undoubtedly will
cause some consternation, but we hope you understand and appreciate
the reasoning.
