Hundreds of Montrealers appear to be the latest victims of a new bank card scam. The Bank of Montreal won't reveal how much it lost or how many customers were hit in the high-tech scam.

Using scanners and hidden cameras, the thieves replicated people's debit cards over the weekend, then cleaned out their accounts.

At one Montreal-area bank branch, someone installed an illegal card-reader on an outside access door. The illegal scanners are known as "Lebanese Loops."

Whenever a customer "buzzed" themselves into the bank branch, the scanner took a reading of the information embedded on the card.

A micro-camera may have been hidden in the ceiling to record people's PIN numbers from over their shoulders.

Using the information, thieves then reportedly created hundreds of cloned bank cards and began withdrawing the illegal funds.

One source said as many as 500 people may have been victimized by the scam.

"Those gangsters are becoming more and more expert at committing fraud of all sorts," said Jacques Hebert, the Montreal regional director of the Canadian Bankers Association.

While Canadian banks generally cover such losses for their customers, the industry won't reveal the numbers involved but the costs are said to be vast. It's an expense that analysts say leads to higher bank fees -- so everyone ends up paying.