I made an API for a bank... I was a third party and made the API by screen scraping their webUI. I sent their devs a link and initially there were positive messages going back and forth. The API allowed you to see balance, transaction history, and make payments. Before long, the API got quite popular, and lots of people were using it to make lots of payments automatically. You know what makes money laundering super e…
TL;DR my understanding is that if you host a banking API you are going to get a lot of scrutiny on who your customers are.
And you can expect an increasing level of compliance regulations heading your way to help regulate and prevent the problems described in the parent.