Sorry to ruin your afternoon, but that PIN number you picked—probably a birthday, month/day combo, or year in the 1900s—is among the easiest for thieves to guess. And if you chose "1234," "1111," or "0000," consider your bank account a slush fund for anyone who steals your card. The firm Data Genetics looked through a database of stolen passwords—mostly for websites—and ranked the popularity of PIN codes, Slate reports. A few tidbits: