In the financial world, the real scandal is often what’s legal, but you still have to watch out for fraudsters. If you don’t pay the costs of screening and monitoring your financial counterparties, you may lose your house.

The never-ending need for financial vigilance came to mind recently when we noticed that the 1920 home of Charles Ponzi was for sale in Lexington Massachusetts. It’s a very large house – 7 bedrooms, 6 bathrooms, 7000 square feet of space (650 square meters) on nearly an acre of land (0.4 hectares).(You can see a picture here.) ...