On your roof is a scarecrow because you're rich. You want to scare away all the poor, non-rich people so you put a scarecrow on your roof.
You wake up the next morning and all of your riches have been stolen! You call the police and they call you a fool (ふ)! Pardon me?! "You basically put an advertisement on your roof telling everyone you're rich. Of course you got robbed, you fool."