Tesco has some explaining to do, a day after admitting that it was hit by a cyber heist.
Money stolen from about 20,000 customers.
Double that number targeted in all.
On Tuesday, the firm was still silent about the exact nature of the hack - online break in, inside job, or some combination of the two.
Jeremy Cook, Chief Economist at World First, said: "Cybercrime is something that the banking sector or anyone dealing with business online has had to deal with for years and years and years now.
"We're going to hear more of these stories over the course of 2016 and 2017 because the focus has shifted for business away from the high street and onto online - that's where the rich pickings are these criminals that want to take advantage of this."
The earlier hack targeted users of the online supermarket - this is more serious.
UK regulators say this is the first time bank account holders have lost money.
An earlier attack on HSBC didn't cost customers any money.
The scale of this breach also unprecedented for any bank.
Cook added: "It's not a huge reputational body blow but I can pretty much say if you went into the high street now and said, 'Would you bank with Tesco after what's happened overnight?'', most people would probably say 'No."
Tesco says it's working fast to repay all customers who lost money.
Now it has to make sure that there's no repeat of the incident.
Otherwise it could gain an unwelcome reputation.