To be honest, this is the silly mistake I've ever made since becoming an active webmaster for several site. The mistake is unforgivable cause as a webmaster you have to be aware of bandwidth usage of your site.
Lesson learn, dont host image on a free site such as Fileden, Photobucket and etc cause once the bandwidth exceed, your site will get kantoi like one of site under my management.
Here is the screenshot taken early this morning.
More over, i'm not the first person to notice that there is image cant be displayed due to bandwidth problem, it's the visitors complain. :( maybe i just not good enough to manage such big site.