Many TGers ask how to stop their images being copied.
The full answer is you cannot.

You could apply a copyright notice embedded into the image.
You should ensure the image is rendered at the right resolution for web use, keeping your hires master safely elsewhere.
You should give the image a meaningful filename.
You should provide Alt Text and Pop-up Text to advise of your copyright.

The following file CSS-Custom Cursors.xar demonstrates an additional approach; the use of images (PNG) as custom cursors.
Hover over the graphics and the red text to see what happens in a modern browser.
While I find these intrusive, it shows the concept and how all the techniques could be combined for a more positive presentation.

Acorn

P.S. Images for Custom cursors do not work in IE, you will only see the fallback cursors.