Merry Christmas from Target, which acknowledged Thursday that a security breach gave thieves access to credit and debit card information for roughly 40 million of its customers. That such a large security breach could occur over a more than two week period is obviously alarming, but it is also a sobering reminder of how vulnerable people are in this era of plastic money.

The breach took place on November 27, the day before Thanksgiving, and continued through December 15, when the Minneapolis-based chain finally shut it down. Significantly it wasn’t Target that revealed the potential theft of customer names, credit and debit card numbers, expiration dates and three-digit security codes but Brian Krebs of Krebs on Security, a prominent security blog. Target operates a store at the Berkshire Mall and the breach apparently involved nearly all of the chain’s 1,797 U.S. outlets.

Representatives of local financial institutions advise Berkshire consumers in today’s Eagle to monitor their credit card accounts for unusual activity (MasterCard and Visa are affected, along with Target store brand cards) and cancel them if necessary. The institutions are reaching out to consumers to alert them to the problem and help them address it. Although many customers may regard credit and debit cards as much the same, credit cards tend to offer better fraud protection.

The access gained to card information of 40 million customers reveals that Target’s security system wasn’t worth the name. It may be difficult for the company to rebound from this disaster given that it may have to make good on a large number of fraudulent purchases. According to Avivah Litan, a security analyst with Gartner Research quoted in a story Thursday by AP technology writer Bree Fowler, the magnetic strip credit and debit cards commonly in use in the US are easily copied. Microchip technology reduces or eliminates this problem, and while it is in use in most of the world, major U.S. banks are resistant because of the cost. Even if the weakness of magnetic strip cards did not play a role in the Target theft, the major banks must do better by their customers and institute better technology.

Consumers will never stop relying on credit cards because of their ease and convenience compared to cash but they must be vigilant at all times. Consumers also deserve better from the giant retail chains and mega-banks that benefit from their consumption.