A friend of mine is about to get married. He and his future wife don't want to spend a lot of money on the wedding invitations. As an (even cooler) alternative, he wants to setup a website about their wedding, not weddings in general but about this particular wedding. To pay for the hosting costs, he plans to put AdSense on it. Now we all know that weddings are a very hot AdSense topic so he's probably going to get a few good clicks.
He intends to spread the word about the site by email to all their friends and relatives. Would you say that this is against the TOS or might be considered click fraught? He wouldn't mention the ads in either the emails or on the site itself. But nevertheless the whole thing is quite risky, wouldn't you say?