Member Rara Avis
Hi, Millette. I'm not sure what kind of help you could want from me. I'm not a lawyer, nor am I the copyright holder (that would be you). Only the owner of a copyright can take the necessary steps to protect their work so its always up to each individual author to do what must be done. Each writer also has to decide how much time they want to invest because, trust me, based on past experience, it's a never-ending challenge.
Here are some links to past discussions in the forums that might be helpful:
I'm sure a search of the Discussion forums for "copyright" or "dmca" would turn up more than just those three threads. It's a discussion that unfortunately pops up all the time.