Today's Liveline provided another timely reminder of how slick some scam artists can be, how they can pray successfully on vulnerable people and why, under no circumstances, you should never give out security details or PIN numbers to unsolicited callers.

Judy, a caller to the show, outlined how her mother came very close to being the victim of a debit card scam artist, who pressurised her into revealing bank account details over the phone.

The man, who had a foreign accent, introduced himself with an Irish name, which was strange in itself. But Judy's mother found him otherwise quite convincing, principally, because of the details he already had.

"They are very very slick…. The frightening part is, the elderly are very vulnerable. They had her name, her date of birth, her home address."

He introduced himself, he said "I'm from your bank". He had her name, her date of birth, her home address, and he had the first four digits of her visa debit card.

The man told Judy's mother that her Visa debit card was about to expire, and in order to issue a new one, he had to verify some details, including the full account number, the numbers on the front of the card, and the security code on the back of the card.

Judy's mother looked at the card, and realised that it was, in fact, due to expire. And given how convincing the caller was, she was inclined to cooperate. Initially, she was a bit dubious, but the caller started to harass her on the phone, insisting that she got her bank account details and an indication as to whether there was "more than €200 in the account".

"He started to harass her. "Go and get your cheque book and give me your bank account details."
… She was on the phone to him for about 20 minutes. She gave him all her details….She gave everything to him. And the minute he had all the information, he hung up."

Quite by chance, as soon as the mysterious caller had hung up, the phone rang again. This time, it was her son, Judy's brother. Recounting what had just happened, Judy's brother had the good sense to get straight into the bank to shut down the accounts. He was put in touch with the bank manager who, as it happens, had the same name as the mysterious caller.

Obviously, this particular scam artist had done some research.

"We were about an hour waiting to find if it had worked. We got there in time. But they had made two attempts to clear out the bank account in the minutes afterwards. It was just lucky that my brother happened to ring at the same time that they hung up."

Not to be deterred, the same brazen scammers called Judy's mother just yesterday. But at this stage, she had been briefed not to give any information out. The minute she heard the accent she said, "If you want to discuss this further, speak with my son. Here is his number."

They hung up.

This case, said Joe, is just another opportunity to remind people that banks and credit card companies will never, under any circumstances, call you and ask you for the security code on your credit or debits cards or PIN numbers for any accounts.

The show featured other callers with similar stories and if you would like to follow up and hear those stories, click here.