Web bugging is the use of these techniques, analogous to
conventional bugging, though not as invasive or intrusive. The
distinction of a web bug should not be confused with the more
benign web spider nor the more malicious, nefarious or
subversive devices such as computer worms. A web bug is any one
of a number of techniques used to track who is reading a web
page or email, when, and from what computer. They can also be
used to see if an email was read or forwarded to someone else,
or if a web page was copied to another website. The first web
bugs were small images. Some emails and web pages are not wholly
self-contained. They may refer to content on another server,
rather than including the content directly. When an email client
or web browser prepares such an email or web page for display,
it ordinarily sends a request to the server to send the
additional content. These requests typically include the IP
address of the requesting computer, the time the content was
requested, the type of web browser that made