No disable web site when quota web traffic is exceeded. Have several options, send email alert, enter a message warning ... It would be more useful. Since disabling the web site, you can annoy users.
I agree in some way... I think that give the option to set "behavior" for bandwidth could be a better solutions... For example: - Do nothing - Display page "bandwidth exceeded" - Disable site "Do nothing" could be usefull if you want to charge $$$ to every user that exceeds if bandwidth limit... Regards