We've had several people imitate our site, not just in overall functionality but to the point of copying specific phrases, design elements, the layout and so on. I agree though that they might be able to get that far, but what they're lacking is the focus that made us create what we did in the first place. Each of these sites has tried to branch out a bit (you know, steal our ideas as a starting point, and build from there) and they've totally missed the mark with each new addition.

Right on about the ethics, too. Someone who builds their business on a purloined platform can clearly not be trusted in general.