After 2 years in retirement, we brought our wonderful GLU-it TO-it widget back in stock. A couple days after putting it online, I checked Google to see if they'd already picked up the image from my website. They had! (Google is some kind of magic, isn't it?)
To my shock, I also discovered that my image of the GLU-it TO-it was on this website. My product image was used without permission. Using someone's image without permission is copyright infringement, and that is serious business.
About 2 years ago, North Light books contacted me about a copyright infringement. An illustrator had copied two drawings from my Colored Pencil Portraits book. The illustrator had made minor changes (hair color) but it was clearly copyright infringement. The drawings were included in a children's book by a small publishing company. Even though the publishers themselves were completely ignorant of the illustrator's copyright infringement, North Light received damages in the amount of $5000, of which I received 10%. Copyright infringement is a serious matter.
We have now begun the rather arduous task of adding my logo to all images on our website to protect ourselves. I'd suggest you do the same with images on your own website or blog. If someone doctors your image to remove your name or logo, the consequences of infringement become huge, including imprisonment.
If you want to use someone else's image on your website, blog or brochure, ask permission. If not granted, there are loads of royalty-free image websites. My current favorite is http://www.dollarphotoclub.com but I've also used dreamstime.com. You pay for the images, but they are very reasonably priced. (Royalty free does not mean the image is free to use. It simply means that you are not charged for each use of the image.)
Need an image of a piece of well-known artwork for illustration? Try Wikimedia Commons. They have royalty-free images of famous artwork, often in high resolution files you can download at no cost. Wikimedia Commons also has photographs of famous people that are in the public domain, like this shot of Charlie Chaplin.
There are also "fair use" exceptions to copyright laws, for purpose of criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research. Using an image for any of these purposes is not copyright infringement.
Re-selling is not a license for use of images that are not your own. Ebay has guidelines that specify that you must use photos and text created yourself. Ebay's rules state:
You're not allowed to use the following if you don't have permission from the owner, its agent, or the law:
I learned my own re-seller lesson a dozen years ago when I used two images from a cruiseline website to advertise our first colored pencil workshop cruise. I assumed that since we were selling their cruises, it would be fine. I was hit with copyright infringement a few months later and paid $1800 for my mistake, even though by that time, the images were no longer viewable on my website. Why would the cruise line do this? They didn't! The cruiseline themselves had purchased the right to use the images from a third party. The third party sued me for damages. Copyright infringement is a big deal.
Did I feel resentment at paying this huge sum that I absolutely could not afford? Truthfully, no. I realized I'd broken the law and a penalty was to be expected. I did, however, feel shame because as an artist myself, I should have known better!
So as easy as Right-Click > Copy Image is, steer clear. If you happen to find one of your images online, you can ask for damages and for removal of the image. You can also notify the website's host of the copyright infringement and they will take the offending website down.