I have been fighting a lot of image hotlinking lately. Hotlinking ranks right up there with the evils of spam as far as a webmaster is concerned. It is bandwidth theft. Since I host several sites on my server and pay for the bandwidth, every illegal hotlink starts to add up.

Hotlinking means rather than copying a file to your own server, you directly link to the file on my site, say, via an IMG SRC tag. Very popular in message forums. My site's server and bandwidth is used to load the image on the other server, acting as a image hosting service. Very, very bad.

There are few methods to prevent the outside hotlinks via .htaccess rewrites, but unfortunately those methods are not full-proof and even lock out some legitimate web traffic. You can check to see if your hotlinking counter-measures are working here.

I've been surprised at how uninformed, uninterested, and angry some people get when I ask them (nicely) to remove the illegal links. Even after explanation, they still think it's the same as a normal URL link, brings traffic to my site, blah blah blah. I even had one occasion when someone hotlinked a design I had done to sell an unrelated item in their eBay auction. They refused to remove it from their auction. I ended the auction for them. Which leads to the ever popular hotlink image swap:

When you point to an outside file, it can change at any time. The image switcheroo is a popular method to stop hotlinking dead in it's tracks. Just remember, when you steal someone's images and bandwidth, you never know what you'll get.