If you have a blog/site with lots of images on it, chances are someone is hotlinking to them. What is hotlinking, you ask? Good question.
According to the all-knowing Wikipedia:
Inline linking (also known as hotlinking, leeching, piggy-backing, direct linking, offsite image grabs and bandwidth theft) is the use of a linked object, often an image, from one site into a web page belonging to a second site. The second site is said to have an inline link to the site where the object is located.
In other words, it occurs when someone is too lazy (or too careful, one could argue, for copyright infringement reasons) with regards to posting images on their site. Instead of uploading an image directly to their own server, they simply use a direct link to another’s hosted image without permission.
Why is this bad? Well, primarily it causes unnecessary strain on sites with limited bandwidth.1 Furthermore, it can be used for phishing attacks and is generally frowned upon among most website developers as poor form. Not to mention when the images being poached are your own original work (as most of your site’s content should be), it would be nice to be able to stop content thieves in their tracks.
Good news, WordPress users, there are a number of free plug-in solutions to help stop/block hotlinking. The one that I’ve been using now for a couple weeks is appropriately named PictPocket. In a nutshell:
PictPocket is a plugin that allows [you] to identify and block content thieves.
Most bloggers are faced with a serious problem: the theft of content or hotlinking.
Indeed, many other sites appropriate images hosted with you to publish on their site.
Pickpocket is a plugin for WordPress that allows [site owners] to identify such content and to block stolen images by placing a discouraging logo.
Basically, PictPocket will identify images that are being hotlinked. Once ID’d, the plug-in provides WordPress administrators with the option to block the image(s) from appearing on external sites. Once blocked, a default “protected content” image (see above) will replace the poached image on the infringing site, thus negatively affecting the infringer’s site and making image thieves think twice before hotlinking. There is also a white list for admins to allow approved sites (say Google, your own site, a friend’s site, etc) to continue using the images. For more on installation and usage, visit the plug-ins official site.