Hi Diane, I can completely relate to the problem of stolen content. I'd come to accept that for one particular project content will be "stolen".
As Greg says, try contacting the webmaster and asked for proper credit and a link back. (Although, make sure you actually want a link back from the site first!) They may be more responsive to this than a request to remove the content...
Another tactic is to embed links to other articles on my site. Make sure the links are absolute links (full domain/path). It would make moving the content around later a pain to manage, but does mean that if the content is copied and pasted onto a different site, you'll be getting the inbound links. Make sure the links a relevant/useful. I like to reference my older content etc.
Hope this helps.