I'm not sure whether this could be useful for you or not, but...just in case ...
You can add copyright information to Photoshop images and notify users that an image is copyright-protected via a digital watermark that uses Digimarc PictureMarc technology. The watermark--a digital code added as noise to the image--is generally imperceptible to the human eye. The watermark is durable in both digital and printed forms, surviving typical image edits and file format conversions--and is still detectable when the image is printed and then scanned back into a computer.
Embedding a digital watermark in an image lets viewers obtain complete contact information about the creator of the image. This feature is particularly valuable to image creators who license their work to others. Copying an image with an embedded watermark also copies the watermark and any information associated with it.
As the gentlemen say here, there's on problem to copy a picture once it's published @the web.