If Stripe turned Evil, how much damage could they do?

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.

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.

I think a better way question is how much damage they might inadvertently do without being evil