Somethingawful.com folks apparently have become really annoyed when folks set up image links directly to their site and have somehow been tagging popular images in a way such that they get replaced by some 'guy' (for lack of a more suitable word) with a note about 'not stealing bandwidth'. What's really annoying is that when you actually look back at said image through normal channels (i.e through their web site), that image is changed as well. I don't know if it is done via 'cookies' (i.e. can I blast my cookies and get the images back) or if remembers your IP locally.

Anyway, I'm not sure when they started it but I first noticed it about a month ago.