I saw on many blogs and also on many answers here on SO that people do Hotlink protection by using this code:
RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http(s)?://(www\.)?mydomain.com [NC]
RewriteRule \.(jpg|jpeg|png|gif)$ - [NC,F,L]
which is also suggested by this tool.
I might be wrong, but isn't it trivial to trick this code? Doesn't a scraper simply need to use a simple subdomains like these ones to bypass the hotlink protection?
http://mydomain.com.scarper1domain.com
http://mydomain.com.scraper2domain.net
EDIT: FYI I use this code that I think is more bulletproof, but i'm happy to read your comments/critics about it.
RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http(s)?://(www\.)?mydomain\.com/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http(s)?://(www\.)?mydomain\.com$ [NC]
RewriteRule .*\.(jpg|jpeg|png|gif)$ - [F,NC,L]