I hate to burst your bubble, but unless you've got time and money to burn, enforcing your copyright is pretty much a waste of energy. The best you can hope for is to have a violators site shut down. Unless it is a registered copyright, you can't sue for cash. Even if it is, you can't get blood from a stone. Hiring a lawyer to sue somebody for money they don't have is also a waste of time, energy, and money. Your best course of action in these cases is to (1) watermark your images as you have, (2) Request that an image credit and contact information be placed with your artwork. Most people are pretty reasonable about that. They just need to be educated. Yes, you will run into the occasional a$$h@!3. Those are the folks whom you report to their web host, and torment relentlessly if it makes you feel better. But unless you have a really cheap lawyer, and or they're a really big corperation and you can get a lawyer to do pro bono it just isn't worth it financially to go after these types with a lawsuit. This is akin to thinking any of us have any real semblence of privacy once we log on to the internet. Know the risks and take them if you will, but do it with your eyes wide open. Don't be fooled into believing for a minute, that just because you have rights, means you are protected.