TypicalSurfer - 1:35 pm on Oct 3, 2012 (gmt 0)
I would use .htaccess to either block their incoming requests for your content or redirect them, you could do a number of things depending on how much fun you want to have with them.
The first thing to do is get the IP that is grabbing your content. You could tail/watch your access log and make a few page requests at their site and from there it's just a matter of how you want to deal with them.
look around for "redirect by IP" for htaccess rules.