Example of attack: The attacker sends emails claiming that the first 500 people to register at the company's new Web site will win free tickets to a hot new movie. When an unsuspecting employee registers at the site, he is asked to provide his company email address and to choose a password. Many people, motivated by convenience, have the propensity to use the same or a similar password on every computer system they use. Taking advantage of this, the attacker then attempts to compromise the target's work and home computer systems with the username and password that have been entered during the Web site registration process.