Yahoo!, AOL, and MSN use the rating system
established by the ICRA. If content at the Web
site goes beyond the rating limits set in the
Web browser software, a user cannot access the
Web site. Concerned parents can set the rating
limits and prevent these limits from being
changed by using a password.
Another approach to content filtering is to
use filtering software. Web filtering software
is a program that restricts access to specified
Web sites. Some also filter sites that use specific
words. Others allow you to filter e-mail
messages, chat rooms, and programs. Many
Internet security programs include a firewall,
antivirus program, and filtering capabilities
combined (Figure 11-37).