Banks are making less of their money from customer-account fees than at any time in the past seven decades as strict government rules and changing consumer behavior squeeze a major source of revenue. After peaking in 2009, the annual account fees collected at U.S. banks have declined, even as the volume of bank deposits has swelled. The fees have dropped nearly 21% to $32.5 billion last year from $41.1 billion in 2009, reversing a trend of fee growth that had lasted since 1942. Fees have become less profitable since 2010, when the Federal Reserve put in place a new regulation requiring that customers had to explicitly opt-in for overdraft coverage. Customers are also making greater use of Internet and mobile banking solutions which make it easier to check balances and avoid overdrafts.