When big banks behave badly, they know that the worst thing they’ll get is a fine; no one is going to end up in jail. Instead, shareholders end up paying the cost, not the bank employees responsible. Shareholders are a diffuse group of investors, many of whom hold shares as a part of a diverse portfolio. They are not the ones who commit such fraud, nor do they have much power to change the bank’s day-to-day operations.
Clearly fines don’t work to prevent misconduct. We should instead rely on the constitutional method of dealing with wrongdoing: the criminal justice system.
Baradaran, Mehrsa, "Commentary: Why We Need to Stop Fining Big Banks Like Wells Fargo" (2018). Popular Media. 287.