Dodd-Frank contained the so-called Durbin amendment which capped debit card fees that could be charged to merchants.  And now banks are charging $5/month to card holders because

[A]s Jamie Dimon, chief executive of JPMorgan Chase, put it after passage last year of the Dodd-Frank Act, “If you’re a restaurant and you can’t charge for the soda, you’re going to charge more for the burger.”

But if you can charge for the burger, why weren’t you charging for it in the first place?  There is a good reason why a bank could charge for the debit card: It is tied to a checking account and the cost of switching to a new bank will mean that the bank can get away with a small fee without much drop off in demand deposits.  So to paraphrase Dimon:

“If you’re a restaurant and you can charge for a burger, you’re going to charge for it, whether the soda is free or not.”