Years ago when we had a business importing products, my bank allowed a charge from Italy that overdrew my account by $2,300. The company shipped an order we had placed 2-3 months before and just used a card we gave them the year before with no warning. I asked my bank why tf they would allow a purchase from overseas to overdraw my account by over 2,000 (which of course incurred a bunch of fees) and they said they do this “as a courtesy to our customers”. I asked if they could not do that in the future, and they said no. Meanwhile I go and try to buy groceries and if it’s $6 over the limit it’s denied for insufficient funds.
Pretty sure it is now legally required for banks to let you opt out of overdraft protection, in fact I think it's all opt in. Because of bullshit scams like this.
My bank seems to have stopped charging overdraft fees altogether a couple years ago and they haven't done it since. Might be more related to all those class action checks I've gotten in the mail than as a "courtesy to their customers" though. Who can say?