I've heard that for many scams it's actually the opposite: They intentionally throw in huge warning flags so that the people who initially "bite" are less likely to have second thoughts later on, and thus the scammer wastes less time chasing false leads. They're basically prequalifying you as a good mark. (There is a good lesson about marketing here too — theoretically "perfect" copy or design may not be ideal for your market, so test and see what provides the best ROI.)