As a surprising number of hits come from image searches, The Company has recently increased our image hotlink protection measures. In practice this means that image requests made by servers other than our own will not be processed.
We do recognise, though, that there are many readers vis Atom and RSS feeds. If you are using Google Reader, images should still appear properly when reading our feeds. If you are using a different RSS reader, feel free to let us know the name/platform in the comments, and we may try to support additional readers as time and volume permit.