You’ll be hearing about this one in the mail. With new government regulations about to radically alter the way banks charge overdraft fees on debit cards, many banks are taking a broad, aggressive approach to make sure the billions of dollars they collect every year in penalty income does not suddenly vanish. Beginning this summer, banks will be required to have customers opt in to overdraft protection. If they do not opt in and try to spend more than is in their account, their debit card will simply not work. Previously, the bank would make the money available and charge a penalty fee of up to $35 or more for the service—banks collected an estimated $20 billion from overdraft fees on debit purchases and ATM transactions in 2009, according to The New York Times. But now, the scramble to convince consumers to opt in is turning into a marketing blitz through email, direct mailing, and telephone appeals.