How do I prevent images from being used on another site?

Question

PHP

Hello, please tell me how can I disable the use of site images by predefined sites?
There are sites that not only take content, but also take pictures directly from the site (which creates a load accordingly).
I would like to be able to substitute a specific picture instead of images (not all, but only certain ones).
There is a rule:
RewriteEngine On
RewriteCond %{HTTP_REFERER} !^ http://(.+\.)?yoursite\.ru/ [NC]
RewriteCond %{HTTP_REFERER} !^$
RewriteRule .*\.(jpe?g|gif |bmp|png)$ /images/empty.jpg [L]
But it substitutes an image for all sites, and is necessary only for certain ones.
Thanks in advance.

Answer 1

Something like this:

RewriteEngine On
RewriteCond %{HTTP_REFERER} ^https?://(.+\.)?badsite1\.ru/ [NC,OR]
RewriteCond %{HTTP_REFERER} ^https?://(.+\.)?badsite2\.ru/ [NC,OR]
RewriteCond %{HTTP_REFERER} ^https?://(.+\.)?badsite3\.ru/ [NC]
RewriteRule .*\.(jpe?g|gif|bmp|png)$ /images/empty.jpg [L]