I remember that there was some debate inside the Creative Commons community about whether ads on a website made the web site "commercial" for purposes of CC-NC.

I remember that there was some debate inside the Creative Commons community about whether ads on a website made the web site "commercial" for purposes of CC-NC. There were certainly many people who felt that it shouldn't, arguing that many sites that people understand as "noncommercial" do include ads. You might want to try to find out a bit more about how this issue has been discussed (and resolved?) within the CC community, for example because it's possible that the person who copied your site might feel that the copy is genuinely "noncommercial". The DMCA takedown process is easy to use, and you don't need a lawyer to use it. However, it's only available if the site is hosted in the United States and the hosting provider has a DMCA agent (which typical hosting providers do). There's also no guarantee that the site will stay down or that you won't end up in court since, by design, the other party has the right to challenge the DMCA notice either by a counter-notice (asserting that the use of the copyrighted work is in fact legitimate) or by asking a court to resolve the dispute (an "action for declaratory judgment"). Also, by design, it's hard to force other people to do things without involving the legal system in some way. :-)