Why Hotlinking Is Theft
Even if You Have Permission to Use a GraphicEach and every time someone looks at a webpage, their browser has to call up the image host and say, "send that image file over to me." It's like making a phone call.
...Multiply that by hours, days, and months, and then multiply that by the number of graphics on a clipart site. You can see why hotlinking puts a substantial load on an image host. That load is bandwidth, and someone has to pay for it.
Luckily, I usually download the images and write down their sources if I use resources from other hosts. However, I did hotlinked to the CC-BY-SA icon since I just copied the code from Creative Commons.1
Now, I’ve got rid of those hotlinked figures.