Direct Linking
Direct Linking is a major problem. The thing is, you make a site. It becomes famous. Then thieves find out about your site and start direct linking to your images. But what is direct linking? It's when somebody links to an image on your site. For example, if:<img src="http://yourdomain.com/image.gif">
appears in your site, it's fine. But if this code appears in freewebs or anybody elses site, it's direct linking. It uses up bandwidth and can make you pay more for your web space. In other words, if an image from your URL appears out of your URL, it's direct linking. And it's BAD. Direct Linking also may be called hotlinking. Avoid doing this at all times and always save to your own server when asked!