The term ''spyware'' is not well defined. Generally it is used to refer to any software that is downloaded onto a person''s computer without their knowledge. Spyware may collect information about a computer user''s activities and transmit that information to someone else. It may change computer settings, or cause ''pop-up'' advertisements to appear (in that context, it is called ''adware''). Spyware may redirect a Web browser to a site different from what the user intended to visit, or change the user''s home page. A type of spyware called ''keylogging'' software records individual keystrokes, even if the author modifies or deletes what was written, or if the characters do not appear on the monitor. Thus, passwords, credit card numbers, and other personally identifiable information may be captured and relayed to unauthorised recipients. Some of these software programs have legitimate applications the computer user wants. They obtain the moniker ''spyware'' when they are installed surreptitiously, or perform additional functions of which the user is unaware. Users typically do not realise that spyware is on their computer. They may have unknowingly downloaded it from the Internet by clicking within a website, or it might have been included in an attachment to an electronic mail message (e-mail) or embedded in other software. According to a survey and tests conducted by America Online and the National Cyber Security Alliance, 80% of computers in the test group were infected by spyware or adware, and 89% of the users of those computers were unaware of it. The Federal Trade Commission (FTC) issued a consumer alert on spyware in October 2004. It provided a list of warning signs that might indicate that a computer is infected with spyware, and advice on what to do if it is. This new book helps shed light on this insidious nightmare created by members of the human race to wreck havoc on the remainder.