CHICAGO (CBS) -- If you’re one of the millions of people who use banking text alerts, beware. Suspicious text messages went out to cell phones across Chicago this weekend warning of “locked debit cards.”

But as CBS 2′s Mai Martinez reports, it’s just a new take on an old scam.

‘Tis the season for shopping, and identity thieves have their eyes on one financial prize: your banking info.

Text messages claiming to be from Fifth Third Bank started popping up on phones this weekend. They said the customer’s debit card had been locked and instructed them to call a number to unlock it.

The text was not sent by Fifth Third Bank.

And it’s not just Fifth Third Bank customers who are being targeted. Chase Bank customer Emiola Dosummu got a similar text.

“It said someone was trying to use my debit card to make a purchase, and so I called my bank and confirmed that it wasn’t true,” Dosummu says.

The Better Business Bureau has had reports from customers of numerous banks.  Director Steve Bernas says phone numbers are generally just randomly produced by a computer somewhere.

“They’re all over the world — third world countries, (with) someone sitting in a coffee shop somewhere,” Bernas says.

He adds: “They have U.S. phone numbers, but they’re not in the U.S. That’s how they stay away from U.S. laws, and they’re very hard to track, and by the time they get to them, they’re gone. They’ve closed up shop, and they’re gone somewhere else.”

CBS 2 tried contacting some of the phone numbers that generated the texts. There were no answers.

Bernas isn’t surprised there was no one on the other line.

“Rest assured they’re going to continue doing it because it works, and identity theft is still the fastest-growing white-collar crime today,” he says.

A spokesperson for Fifth Third Bank says directors there are aware of the texting scam, and they are asking customers to forward the suspicious texts to their security department.