An important task as a webmaster is to prevent your resources to be stolen or your website to be hacked. I had both of this experience now after finding one of my blog got 280gb of bandwidth used on the month of June 2009 and even at 2rd week of July it is already at 350+gb of bandwidth used. Fortunately and unfortunately, I did not even get any warning email and no service disconnection from my Hostgator Shared Hosting account.
This is the stats with around 1k users a day. You can confirm someone is stealing your bandwidth when you see a sudden of increase in bandwidth usage and also see that your image bandwidth is taking a whole chunk of your bandwidth (my case was 96% of the 400+ gb at the end of the month)

Immediatelly I use .htaccess to prevent image hotlinking by adding the code below into the .htaccess file:-
RewriteEngine On
RewriteCond %{HTTP_REFERER} !^http://(.+\.)?website\.com/ [NC]
RewriteCond %{HTTP_REFERER} !^$
RewriteRule .*\.(jpe?g|gif|bmp|png|jpg)$ /no-hotlinking-image.jpe [L]
I know that there is draw back on this but this is the quickest and most popular method to solve this problem and as you see the bandwidth drop pretty quickly after 13 July. After that I have reduce the size of my no-hotlinking-image.jpe to a bare minimal and also remember to include some advertisements on the image.
To find out who is stealing your image bandwidth you can check out the raw access logs. This is where I look for at cpanel admin. Download the logs and if you see some image being load on other url other than yours, visit them and you should see your image (no-hotlinking-image.jpe) display on their page.










