Hotlinking means showing images from other sites which increases bandwidth usage. You can stop Hotlinking in your WordPress site. All you need to do is open .htaccess file present in your WordPress root directory and the given code.
RewriteBase /
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://(www.)?mysite.com/.*$ [NC]
RewriteRule .(gif|jpg|swf|flv|png)$ /feed/ [R=302,L]