Information Technology Reference
In-Depth Information
In addition to passing IP address information to a Web applica
tion, a Web server may log or record where every URL request
comes from (domain name and/or IP address). This information can
be useful, for example, to track the demand for various Web pages,
to identify which pages are most popular, and to explore patterns of
usage. For developers of Web sites, such information can be very
valuable in determining how effective their pages are. Pages used of
ten may be judged more useful or effective than those used rarely.
Similarly, pages that people use repeatedly may have particular
value.
Sometimes, to track particular details of a page, an ecommerce
developer may include a transparent onepixel by onepixel image
on the page, referring to a specific URL. Such a small image repre
sents just one dot, and the image may be transparent. Thus, the user
is unlikely to be able to see this image. (More about such images
shortly.) Despite its invisibility, this small image can be used to
track references to the URL, so the developer can determine specific
usage details of individual sites or groups of sites. This can be par
ticularly useful, for example, if a page contains advertising and the
advertiser wants proof of how often its ad was viewed.
Although all of this information does not automatically identify
specific users, records like these in conjunction with other informa
tion might be sufficient to identify exactly what you used the com
puter to do. For example, if the computer were in your dorm room
or office, it might be safe to assume that you are the only person
who uses that machine. If the computer requires that you log in, the
computer may keep a record of all logins, so a comparison of times
for Web requests and times for logins might provide good evidence
about what you were doing while using the computer.
Although computer systems are not legally required to log Web
usage or logins, the maintenance of some logs can be quite helpful.
For example, if someone sends harassing email or uses a hammer
to attack a computer monitor, then a log might help identify whose
account was being used on that machine at the time. Of course,
once logs are kept to anticipate security questions, the same logs
may be available for other purposes as well. To know for certain
what is happening with the computers you use, you should check
with the school, company, or ISP that supports your computer and
its networking to determine what logs and records are kept. Unless
you know otherwise, you probably should assume that some system
