Probably not a lot. Finance is ridiculously well regulated. You can't just drop tables or whatever; there's ledgers for everything and such. Plus law enforcement & anti-corruption has its hands in lots of stuff.
If the President of the US wanted to be evil, the Illuminati would take actions to make sure none of his plans happen. That's a joke, but the credit cards are somewhat like that. The system is designed to be very chaos resistant.
If someone wanted to be evil, I'd say try something that isn't bank or credit card related. Crypto used to be the thing, but it's no longer the wild west. I'd say something acts like a bank but isn't a bank is more dangerous. Something like construction companies. They have the power to basically give loans and move around lots of money but aren't held back by regulations.
But the law of finance is, in theory anyway, designed to do two things:
1) Punish bad actors after the fact, and, more importantly:
2) Make being evil less of a rational option, and so dissuade people and organizations from breaking the law in the first place
If you've decided to be evil, 2) can't and won't deter you, and it would be easy enough to leak everyone's credit card information. Sure, you'll be punished, but hey, the amount of damage that would cause is probably insane.
Law enforcement could act fairly quickly, probably, but criminals would almost certainly get there first, and once they've got the information, you can't really take it back.
More often, it's punishing good actors before the fact. High risk transactions are blocked until approval. Possibly stolen credit cards are flagged.
If someone wanted to transfer lots of little money to one account, that account would likely be frozen. This also screws over event management companies, but such is the law of finance.
I'm not sure what it's like in places like the US and Singapore, but where corruption and crime is high, the bureaucracy is tighter. Companies that have certain licenses need to set aside a lot of money, they're already rich.
I mean if someone really wanted to be evil, they could leak credit cards, but there's contingencies like 2FA, and weird transactions get blocked. If an airline wanted to be evil, it's a lot harder to stop them.
Probably the same as what already happens with credit card data breaches. Stripe could decide to just start running cards, but it would have to test them as it does not know how much to take from each. That would be short lived. Issuers, networks, etc would put an end very quickly.
Businesses could somewhat easily switch over, they aren’t a monopoly, they’re just the easier option.
They could be more subtle and just start selling data to advertisers, insurance companies, etc. This could increase their valuation by a lot, but idk how competitive they’d become. Every other payment facilitator can do that as well.
They could do what PayPal is doing - steal customer balances by using "risk management" and legal technicalities as excuse. Perhaps that is already starting to happen.
If the President of the US wanted to be evil, the Illuminati would take actions to make sure none of his plans happen. That's a joke, but the credit cards are somewhat like that. The system is designed to be very chaos resistant.
If someone wanted to be evil, I'd say try something that isn't bank or credit card related. Crypto used to be the thing, but it's no longer the wild west. I'd say something acts like a bank but isn't a bank is more dangerous. Something like construction companies. They have the power to basically give loans and move around lots of money but aren't held back by regulations.