This may have changed, but with U.S. banks, the default settings for a debit card were that a bank would let it go into overdraft to offer you the "convenience" of completing your purchase. One fraudulent charge, if you don't catch it in time, could cost you hundreds of dollars in overdraft fees from the bank, and bounced-payment fees from the vendor.

Banks (some, at least), offer you the option to turn off the overdraft convenience, but not all. Still, if you have direct deposit, and your debit card is linked to that account, then even if they don't get much today, they could get more on payday.

Any individual's level of risk depends on how they've configured their accounts.

Yeah i have that option turned off.

I live in a poor neighborhood and have had my cards stolen several times in the last 2 years. The bank always turns them off when there is a series of suspicious purchases (the theives around here seem to favor running from one Wal-Mart to the next), then returns the disputed charges. Maybe I just have a particularly generous bank though.

I have a meth lab across the road and an illegal chicken farm two houses down... but it sounds you like should move ;)

Do you get fresh eggs for not turning them in? :)

With a side of fried rat ;)

If you've been the victim of this sort of thing, why were you saying you've never heard of it being dangerous?

Because you and I have different thresholds for what we consider dangerous, I suppose.

How about "potentially dangerous," then? The fall-out may be minimal or negligble in some situations, and it may prevent people from being able to buy food and medicine in others. Not all incidents are as easily resolved as yours.

I've had friends who've had to borrow money from me just to be able to eat until they got their accounts sorted out and got those refunds from their bank. It was much more of a process for them

In the US banks are required to refund fraudulent charges. That's the law. However they can dispute and investigate charges to confirm whether they are fraudulent and that can take a while. Chase took 8 months to confirm some charges on my card were indeed fraudulent and return my money. The letter from a lawyer may or may not have spurred them along.

When making an online purchase try to stick to vendors you trust and verify that their security certificates are valid. Generally speaking trustworthy online vendors will have done their due diligence and will do things in the accepted standard manner.