Eleven people, including a U.S. Secret Service informant, have been charged in connection with the hacking of nine major retailers and the theft and sale of more than 41 million credit and debit card numbers, the Justice Department announced Tuesday.

The data breach is believed to be the largest hacking and identity theft case ever prosecuted by the Department of Justice, which said the suspects were charged with conspiracy, computer intrusion, fraud and identity theft. Three of those charged are U.S. citizens while the others are from places such as Estonia, Ukraine, Belarus and China.