I recently participated in a discussion about piracy on the internet of one's visual artwork. It is somewhat of a sticky wicket because different interests are in competition here. On one hand, showing one's work to a wider audience is desired. I have gotten commissions from people who saw my work on the internet. My website and blog are a fine way to show off what I do. On the other hand, copying artwork off the net is widespread, sometimes for benign purposes and sometimes as an infringement of copyright. I once saw one of my designs on a tee shirt! While sharing is good, stealing is bad.
I recently installed a spy program called "Tracer" on my internet sites. It tells me what and when was copied. It doesn't tell me who. In the past 30 days, for example, this blog has had 799 page views (not necessarily that many individual viewers.) Two images have been copied and 8174 words were copied. Two links to my work were created. During the same time, my website has had 377 views with no words lifted but 20 images were copied.
I am assuming that those who copy my images are doing so for their own interest or to link me to their sites and are not trying to print out my work to sell, frame, or use commercially. Nevertheless, I am now in the process of updating my images with watermarks, just to make sure.
Another way to protect oneself is to upload images in low resolution and size. This also is a mixed bag. Higher resolution makes nicer viewing but easier to enlarge. I haven't come to a decision yet but right now I am uploading images with about 200dpi and 600 pixels on the long side. Any suggestions?