Shining A Light on Filters
© 1998 Karen G. Schneider, MSLIS
What We Will Cover
• What Filters Are & How They Work
• The Internet Filter Assessment Project
• The Role of Policy
• Other Access Management Options
Filters are tools that block
Internet content. They can:
• Proscribe content
• Allocate resources
• Focus staff/students onto specific
topics
Why Filters?
• Fear of “bad stuff” on the Internet
• Need to control resources
• Belief that filters work
• Lack of confidence in other solutions
Filter Blocking Technologies
• Keyword blocking: blocking word
patterns (breast, butt, death)
• Site blocking: blocking pre-identified
URLs
• Web Rating Systems
Keyword vs. Site Blocking
• Keyword blocking uses software to
identify sites
– Cheap but inaccurate
• Site blocking uses humans to select
and categorize URLS
– Costlier but less inaccurate
Keyword Blocking:
Obliterating In Context
• Typical of Cybersitter, Net Nanny
– “____on, _____on, who’s got the
____on”
– “Because I could not stop for ______”
– “The owl and the ____-cat went to sea”
Keyword and Site Blocking:
Preventing Site Transmission
• Entire files or
directories
are blocked
• Typical of
most filters
Site Lists Prevent Local Control
• Hidden, proprietary information--you
don’t know what’s being blocked
• A shoebox fit for community values-one list for everyone
• Site lists outsource library work to
nonprofessional third parties
Other technologies: blocking by…
• Category
• Specific user or Workstation ID
• Time of day
• Protocol (nntp, ftp, irc…)
Examples of Filter Categories
•
•
•
•
•
•
Job Search
Cult/New Age
Homosexuality
Drugs
Travel
Abortion/Pro-Life
•
•
•
•
•
•
Racism
Religion
Sports
Tasteless
Chat
Vehicles
Types of Filter Software
• Client Software
– Cyber Patrol, Surfwatch, Net Shepherd
• Server-based software--usually a
proxy-server
– Cyber Patrol, Websense, Smart Filter, IGear, X-Stop
Clients
• A client is a single
computer or
workstation
• Client software is
“standalone” (one
copy per computer)
Servers
• Servers are
computers that
provide services to
a network
Many server-based filters work
with proxy servers
• Proxy servers redirect Internet queries
from your browser through the proxy
server
P
Internet
Filter Pricing Examples
• Client Software: $12-40/copy per year
• Server software pricing examples:
– $2,000/50-user license
– $4,000 startup plus $1/computer
monthly license
– $2685 for 50 simultaneous users
How Filters
Work...
Filter Sequence of Events
• You tell your browser to go to a website
• The filter reviews the request….
Is this site or word allowed or
denied by the filter?
Other things on the filter’s mind:
Is access allowed for this user...time
of day...type of resource?
Hmmmmmmmmm...
Let me check and see
Filter Sequence of Events,
Continued
• If the site, word or
other value is NOT
denied, you go
there.
• Otherwise, you
see the denial
page.
Web Ratings: how they work
<META http-equiv="PICS-Label"
content='(PICS-1.1
"http://www.rsac.org/ratingsv01.html
" l gen true comment
"RSACi North America Server" by
"kgs@bluehighways.com" for
"http://www.bluehighways.com/tifap/
" on “2000.08.30T12:22-0500"
r (n 0 s 0 v 0 l 1))'>
So the Rating for TIFAP Is:
• Nudity = 0
• Sex = 0
• Violence = 0 • Language = 1
r (n 0 s 0 v 0 l 1)
Rating System Logic
• If your browser is
set to use RSACi,
• And your threshold
in the language
category is 0,
• You will NOT see the
TIFAP website
How about Library Channel?
• “Selection” tool pointing to 18,000 URLs
• Includes blocking mechanisms
• Three indexed fields
– Title, URL, keywords
Library Channel...
• Didn’t fare well with TIFAP testers
• Browsing environment felt strange
• Retrieval dependent on subject drill-down
• Terms such as penis, herpes, trich were not
good access points
The Internet Filter Assessment
Project
• Librarians tested filters used real questions
from patrons
• Filters were tested in different
configurations
• Most vendors cooperated by sharing fullstrength versions of their filters
TIFAP’s Start:
A Famous Alligator Story. . .
TIFAP Findings
• Fully-configured filters interfered with
question-answering 35% of the time
• Keyword blocking was a major source of
interference
• No filter ever performed flawlessly in either
“direction” (over-blocking or leakage)
Advice from TIFAP
• Test Filters
• Configure Filters
• Filters need feedback and QA tools
Filters are not Magic Cookies
• Filters let through sexually-explicit
material
• Filters block protected speech
• Filters require funding and maintenance
Filters Provide Poor Feedback
• This is not the
level of
information
libraries
provide patrons
when material
is unavailable.
What Else Can’t Filters Do?
• Filters can’t prevent adults from preying on
children
• “Presumption of prurience”: filters can’t
identify intent
• Filters can’t teach appropriate behavior
Minimum criteria for a filter
• Compatible with existing software and
hardware
• Able to communicate with your system
software
• Viewable content
• Content controllable at the local level
• Access controlled by patron status and/or
patron choice
Real-World Tools
for Internet Access
Management
Policy is the First Tool
• policies for behavior
• how to manage people
in public places
Amazing but True
Examples of
Behavior...
Library Patrons Behaving Badly:
• Sex in the bathrooms
• A man belly-crawling through stacks to lick
patrons’ feet
• Irate husband chasing wife with gun
• Shootings
• Mutilating or stealing books & equipment
• Putting Polaroids of penises in books
• Peepers, flashers, starers, followers, etc.
Policy is a Local Solution
• policies are set by
local Boards
• Boards create policy
based upon…
Policy Reflects
School/Community
• What works best
right here, right
now?
• What keeps most
people happy???
Policies for Adults
• These people are not so much adults as they are
employees.
– Right to Privacy?
– Search and Sezure?
• Library policies generally tell adults what they
can’t DISPLAY--not what they can’t READ
– library vs. public library vs.
classroom with books
Policies for Children Reflect
Local Standards for Control
• require parental consent for child
use of computers with Web
access??
• sometimes used
with filtering
Beyond Policy: Other Tools for
Internet Access Management
• Strong PR
• Parental consent
forms
• Privacy screens &
desks
• Computer
positioning
• Filtering
• User education
• Good media &
government
relations
• School Board
cooperation
• Security/
resource tools
Filter Option #1: Filter Nothing
(And Do Nothing Else)
• Does not address
loud public debate
on Internet content
• Lost opportunities
for proactive
leadership
Filter Option #2:
Proactively Choose Not to Filter
• Friendliest
toward
commitment to
open access
• Most difficult to
administer
Filter Option #3:
Filter Everything
• Potential for legal
action
• Negative impact on
information
services
• Bad blood in the
community
Filter Option #4:
Filter Selectively
• Filter children’s
workstations
• Filter some (all) adult
workstations
• Password or leveled
access for staff
Other Internet
Access
Management
Tools
User Education
• It’s Popular
• PR campaign
• Aggressively
proactive-you set the tone
Privacy Screens
• Some find them
annoying
(even MS teachers)
• Can interfere with
group work
• Good for supporting
privacy
Computer Positioning
• “I’ll be right here
(watching) if you
have any
questions”
Privacy-enhancing Furniture
• See http://www.novadesk.com
• Aesthetically appealing, ergonomically healthy
• Expensive and not suited for every setting
Resource Allocation Tools
• Fortres: File-level
security
• WinU, WinKiosk:
– Interface control
– Time-outs
• Cybrarian:
– Security, control
– Time control
Proactive guidance
• Teaches people
what’s good about the
Internet
• Many good sites for
kids
• Very traditional
school work
“Go Lists” make great guides
Some are from libraries, some from
commercial services such as Disney
Get everyone singing
from the same sheet
• Staff
• School Board
• Media
• Government