Up to 40 Million Credit Cards Used at Target Could be Compromised

Going back to Black Friday; Secret Service investigating

A breach of credit and debit card data at discount retailer Target may have affected as many as 40 million shoppers who went to the store in the three weeks after Thanksgiving, the retailer said Thursday. 

Late Wednesday, the Secret Service, which is charged with safeguard the nation's financial infrastructure and payment systems, confirmed it was investigating the breach.