First off, awesome plugin. My traffic has increased dramatically in just one day of use, however... I have found a few bugs.
For starters, everyone who subscribes through my site using an RSS feed gets the hotlinking error. I've added Feedly and Feedburner to the whitelist for the time being, but there are hundreds of RSS services, and I don't want to block out my readers who choose to use, uh... readers.
Secondly, if you use a .png as your Favicon instead of a .ico file, you'll notice that the hotlink image is applied to that, hilariously enough. I was wondering why my Favicon turned into a black box, and sure enough. You can see that in action here: http://www.unfinishedman.com/
Any chance we could see a fix? I'll gladly donate to expedite the process. :)