Linux Genuine Advantage™ works by checking our licensing server periodically to make sure that the copy of Linux you are running is Genuine. This is determined by whether you have paid us the appropriate licensing fees. If you are out of compliance, and are past the grace period, logins to your machine will be disabled until the license fees are paid. How to log in to enter the license key when logins are disabled is left as an exercise for the reader. Finally! Linux users can experience a feature that until now remained the exclusive domain of proprietary software.