How to block visitors from specific website?

Sometimes you do not want traffic coming from specific websites. This is sometimes useful to block hot linking files or for any other reason.

To block single site use .htaccess code:

RewriteEngine on
RewriteCond %{HTTP_REFERER} sitetoblock\.com [NC]
RewriteRule .* - [F]

To block multiple sites use code

RewriteEngine on
RewriteCond %{HTTP_REFERER} sitetoblock\.com [NC,OR]
RewriteCond %{HTTP_REFERER} secondsitetoblock\.com
RewriteRule .* - [F]

If your server is not configured with FollowSymLinks you may receive 500 Internal Server error when using the code. To solve this add line Options +FollowSymlinks below RewriteEngine on.