When I was learning to program through a bootcamp I spun up an elastic beanstalk instance that was free but required a credit card to prove your identity. No problem that makes sense - it's an easy way to prove authentication as a bot can't spam a credit card (or else it would be financial fraud and most likely a felony).
Amazon then charged me one hundred thousand dollars as the server was hit by bot spam. I had them refund the bill (as in how am I going to pay it?) but to this day I've hated Amazon with a passion and if I ever had to use cloud computing I'd use anyone else for that very reason. The entire service with it's horrifically complicated click through dashboard (but you can get a certification! It's so complicated they invented a fake degree for it!) just to confuse the customer into losing money.
I still blame them for missing an opportunity to be good corporate citizens and fight bot spam by using credit cards as auth. But if I go to the grocery store I can use a credit card to swipe, insert, chip or palm read (this is now in fact a thing) to buy a cookie. As opposed to using financial technology for anything useful.