SBoondock Bank has an ATM with six-digit PINs. Until a year ago, all PINs were randomly assigned. Since then, an “account representative” explains the PIN process to each new customer and helps them...

SBoondock Bank has an ATM with six-digit PINs. Until a year ago, all PINs were randomly assigned. Since then, an “account representative” explains the PIN process to each new customer and helps them choose a PIN. The rep says to pick a date, because they’re easy to remember. Now 25 percent of all PINs are 6-digit dates.