Target said today that it was investigating a large-scale security breach involving stolen credit and debit card information for 40 million of its retail customers nationwide.

Concerned Target Corp. customers took to Twitter on Thursday to express concern and frustration about the disclosure that hackers stole credit card and debit card information from some 40 million of the retailers' customers.

Several wondered what they should do to protect themselves. Some said they were immediately canceling all of their credit cards to avoid the potential for fraud. Others said they planned to stop shopping at Target.

If the concern on Twitter was any indication, Target has quite a public relations fiasco on its hands.

"Target why are you storing the security codes of credit and debit cards that are swiped at your stores?" one angry customer wrote on Twitter.

Target said Thursday that data on 40 million of its customers’ credit and debit card accounts may have been breached by cyber-crooks during the busy holiday season.

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The Minneapolis retailer said the unauthorized access -- which occurred between the Nov. 27 start of Black Friday weekend and Dec. 15 -- may mean that criminals now have shoppers’ names, payment card numbers, expiration dates and three-digit security codes at their disposal.

The breach affects Target patrons who made purchases at U.S. stores, not online, the company said.

Target said it is working closely with law enforcement to determine the scope of the problem. The company suggested that any customers who notice fraudulent activity on their cards immediately notify the Federal Trade Commission.

There are several things consumers can do to protect themselves. Most important, they should check online statements of any suspicious activity and immediately contact their banks if they find any.

Below is some recent chatter about the data theft on Twitter:

 How do I know if my personal information is still secure? @Target


Twitter: @spfeifer22