Information Technology Reference
In-Depth Information
tionable” content. In this context, filters typically have the goal of
limiting Web access; in particular, software filters commonly are
used in today's society to prevent children from accessing objection
able materials on the Web. And thus, we encounter our first social
difficulty related to filters: There is no universal consensus regarding
what might be objectionable. As a simple example, people in
Scandinavia generally are much more tolerant than people in the
United States regarding sexual content, but generally less tolerant re
garding violence and guns. Even within the United States, people dis
agree about the extent information regarding such matters as birth
control or guns should be available to minors. Similarly, obscenity
laws within the United States often refer to local standards of de
cency—a standard that is particularly difficult to interpret in the con
text of the international Internet. On a related matter, politicians,
community leaders, and parents debate the extent to which medical
information should be available over the World Wide Web. If chil
dren are not allowed to view healthrelated clinical information for
parts of the body (such as genitalia), then the question arises as to
whether children should be allowed to search online library catalogs.
Once developers of software filters determine what is and is not
objectionable, the next challenge is to determine just what blocking
of materials a filtering program should provide. Several issues arise:
Should filters apply to images only, text only, sound only, or
some combination of these?
Does “effective” mean that 100% of all “objectionable” ma
terial is blocked? or 95%? or 80%?
To what extent should “effective” filters allow free access to
“nonobjectionable” materials? Should 100% of these materi
als be available? or 95%? or 80%?
Should filters block materials that are encrypted? For exam
ple, if an image were sent as a text file (perhaps using ASCII
characters), then the text might be meaningless but a simple
reinterpretation of the file as an image might allow viewing.
If an image were sent in binary format as a number, should
filters block certain numbers as potentially representing ob
jectionable pictures? (Is 10010110011 an objectionable num
ber or not, and how would you justify your answer?)
If filters are to decode encrypted materials, how will the fil
ters know which encryption scheme is used and how to de
