Protip: Do not hotlink.
So I had forgotten to add a rewrite rule to my image directory that disallowed hotlinking (to the extent that one can disallow such things). Hotlinking, in case you don’t know, is when you refer to an image or other resource on someone’s website while creating content on someone else’s website. The most common scenario is referring to images on someone else’s site, although I’ve seen cases where CSS is used as well.
The reason this is frowned upon is because you (in general) have to pay for the bandwidth you consume, so hotlinking an image causes someone else’s bandwidth to increase, without anyone actually meaning to visit their site.
In this case, a picture of some beer bottles I’d posted after I’d lost my job was linked by some poor schmuck in a forum. He’d used it as the last word in a sentence: “Now we can all go over to truepatriot’s house and have a bunch of [image of beer]”:
Well, this was just too good to pass up:
The moral of the story is, do not hotlink unless you know you won’t be made a fool of.