A keylogger, sometimes called a keystroke logger, key logger, or
system monitor, is a hardware device or small program that
monitors each keystroke a user types on a specific computer's
keyboard. As a hardware device, a keylogger is a small battery-
sized plug that serves as a connector between the user's
keyboard and computer. Because the device resembles an ordinary
keyboard plug, it is relatively easy for someone who wants to
monitor a user's behavior to physically hide such a device "in
plain sight." (It also helps that most workstation keyboards
plug into the back of the computer.) As the user types, the
device collects each keystroke and saves it as text in its own
miniature hard drive. At a later point in time, the person who
installed the keylogger must return and physically remove the
device in order to access the information the device has
gathered. A keylogger program does not require physical access
to the user's computer. It can be downloaded on purpose by
someone who wants to monitor activity on