employees whose addresses they have not harvested. Many spammers use programs called web spiders to find email addresses on web pages. Usenet article message-IDs often look enough like email addresses that they are harvested as well. Spammers have also harvested email addresses directly from Google search results, without actually spidering the websites found in the search. Spammer viruses may include a function which scans the victimized computer's disk drives (and possibly its network interfaces) for email addresses. These scanners discover email addresses which have never been exposed on the Web or in Whois. A compromised computer located on a shared network segment may capture email addresses from traffic addressed to its network neighbors. The harvested addresses are then returned to the spammer through the bot-net created by the virus. In addition, sometime the addresses may be appended with other information and cross referenced to extract financial and personal data. A recent, controversial tactic, called "e-pending", involves the appending of email addresses to direct-marketing databases. Direct marketers normally obtain lists of prospects from sources such as magazine subscriptions and customer lists. By searching the Web and other resources for email addresses corresponding to the names and street addresses in their records, direct marketers can send targeted spam email. However, as with most spammer "targeting", this is imprecise; users have reported, for instance, receiving solicitations to mortgage their house at a specific street address — with the address being clearly a business address including mail stop and office number. Spammers sometimes use various means to confirm addresses as deliverable. For instance, including a hidden Web bug in a spam message written in HTML may cause the recipient's mail client to transmit the recipient's address, or any other unique key, to the spammer's Web site. Users can defend against such abuses by turning off their mail program's option to display images, or by reading email as plain-text rather than formatted. Likewise, spammers sometimes operate Web pages which purport to remove submitted addresses from spam lists. In several cases, these have been found to subscribe the entered addresses to receive more spam. When persons fill out a form, it is often sold to a spammer using a web service or http post to transfer the data. This is immediate and will drop the email in various spammer databases. The revenue made from the spammer is shared with the source. For instance, if someone applies