There is a popular misconception that as payments made in shops and on websites with Visa Electron debit card are checked with bank to see if there are sufficient account funds, that one can’t go overdrawn if one just uses Visa Electron, but one can, as unlike withdrawing cash from a ATM the amount is not debited from the account straight away but takes 3 to 5 days, so one can make multiple payments with a check being against only balance that does not include the other payments. This was not clear to me, and on that card I was unable to check my balance as it did not work in ATMs or at Post Office, , only for debit payment at shops, but that is another story. I found this all this to my cost in unauthorized bank charges which I can ill afford and I will try to reclaim, but that is a real hassle.
This make all the more problem that government is insisting people have benefits and pensions paid into bank accounts where they fall into this trap as well, which would not be case if just paid out as cash at the post office.
And also with under 18s often getting accounts with visa electron, which they can use online, and it seems according to an article at gambling sites.