The internet is a powerful tool and internet users should use it responsibility. Internet etiquette refers to the standards for proper behavior on the Internet. Hotlinking to images is a violation of Internet etiquette.
The majority of image hotlinking comes from blogs, discussion forums, and websites like MySpace and Stumbleupon. As a long time Internet user, I can tell you that image hotlinking has always been a major concern. While it’s questionable on whether or not hotlinking is copyright infringement, it is a theft issue.
Hotlinking, also known as bandwidth theft is direct linking to a web site's files. When you link to an image on someone else’s server instead of saving the image to your computer and uploading it to your blog you are stealing that websites bandwidth.
Most websites have a limited amount of data transfer (or bandwidth) allowed. If they go over this limit, it costs them extra. Stealing bandwidth therefore unnecessarily increases the cost of hosting. Also, with many hosts limiting the amount of bandwidth a site can use monthly, their site could be shut down for exceeding bandwidth quota.
Though it is the webmaster's responsibility to prevent the unauthorized remote loading of images from their site by uploading an .htaccess file to their server, anyone hotlinking is doing something that truly is unethical. As a webmaster, hotlinking is certainly not something that I appreciate.
If you wish to republish an image, the proper thing to do is to save the image to your computer and upload it to your blog or a free image host. Make sure that you obtain permission from the original author before you upload it and before publication to your blog takes place.
The solution for webmasters dealing with hotlinking is to use an .htaccess file. It’s very simple to implement and it works beautifully!
If you are using Wordpress, there is a hotlink protection plugin that you can install which fights bandwidth theft.
A word to the wise, please don't hotlink. Hotlinking is definitely not proper Internet etiquette.