I reported such a site to adsense the other day - it had a lot of popular forums on it so I doubt it will last long. Well worth doing the same if yours is also using adsense ads.
In this case it looked like a frame but actually the content had been copied onto their own site.
This one was very much against adsense policies, but they aren't very good at dealing with things like this (no staff to police their system). A DMCA to the host might be more effective but takes more effort.