Unfortunately, there's not too much you can do if you're stuff gets copied without including your resource box. However, the benefits to article marketing outweigh that fear!
If your content is good, you will see results from it. Be patient, though, because it can take some time to build up momentum. However, you can benefit from these articles for months or even years. You never know when someone is going to find your article, like it, head to your site, and become a loyal customer!