actually, for some years now, you don't even have to make the claim - intellectual property automatically has copyright protection. when you capture an image, it's copyrighted.
you can also register your work in DC if you're in the us, but that just sets you up to be able to seek punitive damages if you find someone copying your work.
the sad fact is that there's not really too much small operations can do if they find infringement - the legal costs will kill you.
wwith the common perception that data wants to be free, piracy has just increased. I sell photography, and have always hada policy of giving away web sized versions of images in return for a link. i keep the hi-res images protected til purchase