Target says that about 40 million credit and debit card accounts may have been affected by a data breach that occurred just as the holiday shopping season shifted into high gear.
The breach was first reported by security reporter Brian Krebs.
Target confirmed the breach, and published a Q&A for consumers.
Here are some perspectives from security and business experts:
"While this search for the truth is happening, the issue damages the trust Target have gained in mobile and calls into question how sales (will) trend in January." -- Brian Sozzi, chief executive officer of Belus Capital Advisors, via Reuters
"This is a real blow. I think it will hurt their sales to some extent. I think it's going to cost them money, it's going to affect their earnings. But mainly, it's going to impact their image." -- Retail analyst Howard Davidowitz, via mprnews.org
"Presuming this is all true, it's probably one of the most serious things you can have happen, because it affects not only your store operations, it affects the lives and financial security of your customers." Jim McComb, Twin Cities retail analyst, via TwinCities.com
"We see breaches across all sizes of companies. You see the stories about the big ones in the news, but breaches are affecting companies all across the board." -- Mike Donovan, Beazley Breach Response, via USA Today
"Criminals go where the money is. Typically, criminals will steal credit card information and then sell it. There's a very elaborate economy built around this type of crime. That's a very valuable asset that can be obtained completely through remote Internet access." -- Michael Sutton, vice president for research at security company ZScaler, via via New York Times
"Target's first priority is preserving the trust of our guests and we have moved swiftly to address this issue, so guests can shop with confidence. We regret any inconvenience this may cause," he said. "We take this matter very seriously and are working with law enforcement to bring those responsible to justice." -- Gregg Steinhafel, Target's president and CEO, via statement