boneprone is right
but I use them on my TGP so I didnt want to change that links and copy images etc.
so I added this piece of .htaccess
RewriteEngine On
RewriteCond %{HTTP_REFERER} !^http://www.smashingthumbs.com.* [NC]
RewriteCond %{HTTP_REFERER} !^http://smashingthumbs.com.* [NC]
RewriteCond %{HTTP_REFERER} !^http://www.smashingthumbs.com:80.* [NC]
RewriteCond %{HTTP_REFERER} !^http://smashingthumbs.com:80.* [NC]
RewriteRule /*
http://www.smashingthumbs.com/hotlink.gif [R,L]
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Smashing Thumbs TGP