In the US there is a not so hidden secret blacklist (actually a couple of them, different banks use different ones) where if you get on that blacklist the bank will refuse to open an account for you. Its an unaccountable list that unfairly prevents tons of people from needed banking services in this hyper-connected and hyper-financialized economy.
Also, a personal theory is that banks that provide high fee services for people in that black list (used to be called the chexx system or something similar) are much more likely to quickly put someone on it.
Various credit score systems played the same role here, and banks banning too many people despite always promising otherwise is what finally brought down the regulation hammer on them.
