I've already complained about those deep-link preventers based on the referrer being pretty stupid when you include your images in the RSS feed - because then aggregators can no longer display the images without further ado, since the deep-link prevention kicks in. Pretty annoying - especially when the aggregator is displayed in a web browser, because then it caches the prevention image and when accessing the original pages, it no longer loads the correct image, but first has to be forced to refresh.