Information Technology Reference
In-Depth Information
a site may not require you to complete some forms, or it may be able
to fill forms with information you have supplied previously—mak
ing your interactions easier the second time you visit the site.
Regarding privacy, Web browsers send cookies only to the sites
that they came from initially; browsers do not distribute cookies that
originated on one site to other sites. Thus, one Web site cannot directly
determine what other sites you might have visited. We have, however,
already noted that a Web site may contain small (one pixel), transpar
ent images. Sometimes these images actually come from other Web
sites, in which case they are called
Web beacons
or
Web bugs
. Because
these special images are associated with specific Web sites, those sites
also have the capability of storing cookies on your computer—even if
your Web request only asked for a page that happened to contain Web
beacons or bugs. Cookies obtained in this way are called
foreign cook-
ies
or
third-party cookies
. In recent years, some Web companies, such
as DoubleClick, have contracted with various commercial Web sites for
general tracking of customers. In such cases, a Web beacon of the
DoubleClick or other Web tracking company is placed on a commer
cial Web site. When you view the commercial site, you also load the
Web beacon for the tracking company, and your browser will return
any cookie related to that information to the Web tracking company.
Because cookies identify your computer, and because the tracking com
pany knows about the current page you are viewing, the tracking com
pany can maintain a log of what commercial sites you have visited over
time through its Web beacons. The tracking company may not know
your personal identity, but it can keep track of what contacts your
computer has had with the Web sites it is monitoring. Log information
can provide commercial sites with valuable information about the in
terests and preferences of their users, so it is not uncommon for com
mercial Web pages to contain Web beacons.
Up to this point, we have discussed three ways that sites or
servers can record information about your Web browsing:
1.
By logging your computer's IP address in interactions be
tween your browser and a Web site
2.
By placing cookies on your computer or in your account
3.
By tabulating thirdparty cookies by Webtracking companies
