One comes immediately to mind: financial services for the poor. Check cashing, payday loans, overdraft fees, etc.. Fortunately the CFPB has been fighting in their favor but the scales are still tilted in an extreme direction. It is a social injustice that the middle-upper classes enjoy mostly free banking while the poor have to pay a significant portion of their income to access liquid cash.
Disclaimer: I work for a startup that provides low-cost banking services to the poor. http://www.onefinancialholdings.com/bee/