Hot link protection works best by checking the referrer, not the IP that is actually getting the data since they are only following the link they got when they visited the page that is hot linking your data.
This way if 100 more sites start to do it, the same rules in effect block them as well.
For this to work properly, you have to have the unauth image has to be outside of the area you are protecting.
As an example... on one of my weather sites, I have static created content (updated by cron once a minute) that is in a directory called grlevel3
So, IN that directory /grlevel3 , I have an .htaccess that includes:
RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^.*.myvzw.com/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://www.tnetweather.com/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://www.grlevelx.com/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://test02.tnet.com/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://cumulus2.tnet.com/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://grlevelx.com/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://test04.tnet.com/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://cumulus.tnetweather.com/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://weatherbus.com/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://www.weatherbus.com/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://weather-watch.com/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://www.weather-watch.com/.*$ [NC]
RewriteRule .*\.(gif|GIF|jpg|JPG|png|PNG)$ http://www.tnetweather.com/images/UNAUTHWEATHER.gif [R]The entries up to the last one are the sites that I allow to hotlink. Most of them primarily because I have used them in forums that are weather related and I want them to be allowed.
The last entry points to the image that provides the unauth image. It protects any image, jpg, gif, png located in that directory or lower. The block image In this case, it looks like:
If someone goes directly to the image, they will see it just fine, same as if they are referred by any of the allowed sites. If they go to another site which links to content there, it shows up in the visitors browser.