Definition of Intruder Lockout
Some systems monitor failed Authentication attempts, and if too many attempts to sign on with a single account are detected, the Account is locked. This mechanism is intended to deter an Intruder, who may attempt to guess the password for one or more Accounts.
Intruder Lockout may also be triggered by users who persistently mistype their own passwords (e.g., with the Caps Lock or Num Lock key depressed).
Most systems differentiate between a locked and Disabled Account.