Watermark hotlinked images

[Pixel-Artist]

I saw somewhere this is possible.

Can anyone give me a link?

[bokeh]

Check my signature for a watermarking script but you would be much better off adding a rule to .htaccess to stop it. Try this:<IfModule mod_rewrite.c>
# stop hotlinking
RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER}---%{HTTP_HOST} !^http://([^/]+)/.*---\1$ [NC]
RewriteRule \.(gif|jpg|jpeg)$ - [F,L]
</IfModule>