This discussion reminds me of my experience with Bank of America years ago, when online banking and bill pay was in its infancy.
I had, for the first time in my life, FOUR overdraft fees in one month! What?
I immediately called the CSR and begged them to remove them, as a good customer with a perfect payment record up to that point, etc. And they did it. Whew.
A few months later, it happened again!
What they were doing was changing the order of deposits and debits to generate OD fees.
Say you look at your account on Monday, and it shows a deposit coming in on Tuesday, and debits going out on Wednesday.
Then you check again on Friday, and it shows the deposit came in Wednesday, after the debits on Tuesday, and now you owe four OD fees, because they take out the biggest one first so all the small ones that follow are overdrafts as well.
So I called the CSR a second time, but this time, "because I had a history of OD fees", they wouldn't credit me. Burn!
I remember distinctly telling the CSR that the bank was going to get sued for this, and I immediately changed my main checking account to USAA, who I'm still with (and no OD fees, ever).
Sure enough, a few years later, I got a letter in the mail regarding a class action lawsuit vs Bank of America.