A second Russian has plead guilty to the largest ever US cyber crime:

Prosecutors said that as far back as 2003, the men worked to install “sniffers” designed to comb through and steal data from computer networks of financial companies, payment processors and retailers.

Prosecutors said the defendants then used an array of computers to store and ultimately sell data they collected.

They said Smilianets was in charge of sales, selling data to trusted identity theft wholesalers, selling credit card numbers for $10 to $50 a piece depending on country of origin.

The scheme ultimately caused banks and credit card companies to suffer hundreds of millions in losses, including more than $300 million reported by three companies alone, prosecutors said.

Sixteen companies’ networks were infiltrated, including those of Nasdaq OMX Group Inc, 7-Eleven, France’s Carrefour SA, JC Penney Co, JetBlue Airways Corp, a Visa Inc licensee, and Heartland Payment Systems Inc, prosecutors said.

Smilianets faces up to 30 years in prison when he is sentenced by U.S. District Judge Jerome Simandle on Jan. 13. His lawyer did not immediately respond to a request for comment.