You can stop others from hotlinking your site images by placing a .htaccess file in your website main directory:
RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://(www\.)debian-tutorials.com/.*$ [NC]
RewriteRule \.(gif|jpg|png)$ http://www.debian-tutorials.com/wp-content/uploads/2012/12/hotlinkimage.png [R,L]
- The first line of the code enables the rewrite.
- The second line will block any website other than your own.
- The No case [NC] code will match the url regardless of being in upper or lower case letters.
- We allow empty referrals on the third line.
- The last line matches any files ending with the extension gif jpg and png. The hotlinked image will be replaced by the image specified here. You can also use here a link from another domain.