The Web Bug FAQ

by Richard M. Smith (
November 11, 1999 Version 1.0

Web Bugs Basics

1. What exactly is a Web Bug? 2. Why are Web Bugs invisible on a page? 3. Are Web Bugs always invisible on a page? 4. Are all invisible GIF images, Web Bugs? 5. What other names are Web Bugs known by? 6. What information is sent to a server when a Web Bug is viewed? 7. What are some of the uses of a Web Bug on a Web page? 8. Where can I find Web Bugs being used? 9. How can I see a Web Bug on a page?

Web Bugs in Email Messages

10. What kinds of uses does a Web Bug have in an Email message?
  1. A Web Bug can be used to find out if a particular Email message has been read by someone and if so, when the message was read.
  2. A Web Bug can provide the IP address of the recipient if the recipient is attempt to remain anonymous.
  3. Within an organization, A Web Bug can give an idea how often a message is being forwarded and read.
11. Why are Web Bugs used in "junk" Email messages?
  1. To measure how many people have viewed the same Email message in a marketing campaign.
  2. To detect if someone is viewed a junk Email message or not. People who do not view a message are removed from the list for future mailings.
  3. To synchronize a Web browser cookie to a particular Email address. This trick allows a Web site to know the identity of people who come to the site at a later date,
12. What are some of the Email marketing companies who are known to use Web Bugs? 13. What companies have used Web Bugs in Email marketing campaigns? 14. What do Web Bugs in Email messages look lile?

Advanced topics

15. Is there any method of removing Web Bugs from HTML pages? 16. Why don't Web site privacy policies ever mention Web Bugs? 17. Are the use of Web Bugs legal? 18. Are the use of Web Bugs unethical? 19. Can newsgroup messages be bugged also? 20. Can Yahoo profiles be bugged?