Attorney: Bank tellers may be stealing your account information

There's a warning about identity theft and how thieves can rob your bank account, with just a simple phone call.

Authorities say these modern-day bank robberies involve thieves calling your local bank directly to steal your bank account information.

They will call asking to change the phone number on an account, or order checks to get money from another account.

And you may not believe the accomplice. Prosecutors say the stolen info can come from a bank teller.

Cyrus Vance, Manhattan's top attorney, says bad tellers are often part of the larger identity theft rings.

"Bank tellers have access to very confidential data," said Vance. "They're selling that (data) to individuals on the outside who will then take that information and turn it into credit cards or checks."

One woman, who did not want to show her face, Says someone stole thousands of dollars from her account just weeks before the biggest day of her life.

"We had been working for about a year to save up a lot of cash to pay for our entire wedding and it was gone," she said.

The victim says she had no idea a bank teller had stolen her identity along with 28 other customers until she received a letter from her bank.

Chase told her: "A former employee may have accessed your account information without authorization and gave it to someone outside of Chase."

In response, Chase told ABC News: "As soon as we discovered this, we immediately called authorities, fired the employee and reimbursed the customers. We're sorry and angry this happened."

But Vance says not all banks aggressively fight and report these crimes.

"I think some banks need to be doing more. If it's not reported to law enforcement, it's just an invitation for that criminal to keep the money and go onto the next account or next bank," he said.

The American Bankers Association tells ABC News that banks use many safeguards to prevent fraud, including sophisticated software to monitor employee access of customer accounts.

They also say that because customers are always protected against fraud, the bank will cover any loss.