http://www.robtex.com/dns/usaescorts.com.html
I had a long and noble white knight reply written but of course my browser crashed.
Anyway, my advice would be a (probably easy and cheap to get) cease and desist letter from an actual attorney. These dickheads operate under the assumption that providers (esp. independent ones) are too scared, too dumb, or too strung out to make a stink about this kind of theft. Don't be one who perpetuates that idea.
This is your intellectual property, and the very reason so many providers place watermarks on their pics. Even if it was good and/or free publicity for you, no doubt the webmaster is tracking how traffic to and from that page is going and to/from where. Not to mention that if the site rips someone off or what-have-you, it will look as bad or worse on a named provider than on some faceless webhost.
I'm no lawyer and not an uber-guru with this whole intertubes thing, but I'd bet that C&D letter would get their asses in gear.
Good luck and kick some ass.
WS