preventing hotlining

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I want to prevent other sites hotlinking to images on my site which
appears as the urls:

I have added the following lines to.htacces
RewriteEngine On
RewriteCond % ^http://(.+\.)?twinisles\.com/ [NC,OR]
RewriteCond % ^http://(.+\.)?japandesu\.com/ [NC,OR]
RewriteCond % ^http://(.+\.)?japan.twinisles\.com/ [NC]
RewriteRule .*\.(jpe?g|gif|bmp|png)$ - [F]

However when I test it on sites such as
the images still appear.

What am I doing wrong?

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