Why would I exceed my bandwidth limit in cPanel
There might be a few things that can cause your website to exceed your monthly bandwidth limit.
1. Because of the high volume of visits to your website, you may exceed your bandwidth limits, especially if you have your website image and media intensive.
2. You may be attacking your website. This means that someone could be sending hits to your site with a program, to use up its bandwidth so that site will be unavailable.