You can thank terrorists for that, since banks were relatively free with servicing customers until 9/11. After that, the governments all over really started to reign down on where the money is going and how its being spent. A lot of developed countries these days have their own kyc/aml regulations for their banking system.
And it doesnt help that a lot of companies invest very little money into their IT Security either.
It doesn't really matter how much money they invest in IT security anyways. With that much valuable info in one place, even inside jobs become profitable and likely.
Centralized data storage systems can't really be secured in this day and age.