You have a hundred dollars in your account. You pay 20 dollars for gas. Later, you pay 30 dollars for a medical copay. Finally, you pay $110 for groceries. If you were a customer of Wells Fargo, the bank would reorder the transactions so that the grocery purchase appeared to have been made first. By doing so, the bank could charge you three separate overdraft fees ranging from 25 dollars to 35 dollars each. If the bank left your transactions in the order in which you actually made them, it would have only been able to charge you one overdraft fee.
The practice of reordering debit card transactions to maximize overdraft fees was the subject of a class action lawsuit called Gutierrez v. Wells Fargo. In Gutierrez, the Supreme Court upheld a 203 million dollar judgment against Wells Fargo for manipulating debit card transactions to recover unjustifiable overdraft fees from unsuspecting Californians.
Over 30 banks have settled lawsuits related to the reordering of debit card transactions to maximize overdraft fees. In spite of that history and its loss in Gutierrez, Wells Fargo is continuing to force the citizens of the other 49 states to litigate claims related to their overdraft fees through arbitration.
On July 19, 2017, the Consumer Financial Protection Bureau released a rule that would ban mandatory arbitration clauses designed to keep people injured by financial institutions out of court. The rule is scheduled to take affect on March 19, 2018.