In its most recent report, "Out of Balance," the consumer advocacy group found that debit cards are the largest source of account overdraft fees for banks and credit unions. Debit card point of sale and ATM overdrafts cost consumers $7.8 billion in 2006, which represented 45 percent of the $17.5 billion the financial institutions received in overdraft fees last year.

In hopes of reducing overdraft fees, the center is supporting legislation sponsored by Rep. Carolyn Maloney, D-N.Y., and Rep. Barney Frank, D-Mass., that would require banks and credit unions to warn their customers before authorizing an electronic overdraft. The House recently held a hearing on the legislation.

And financial institutions should restrain their fee frenzy and stop routinely allowing consumers to withdraw funds that exceed their account levels, only to slam them with overdraft charges.