Citigroup, network under attack by hackers. The details of 200 credit cards have been spied on

Citigroup, the world's largest financial services company, announced this morning that some hackers had breached the bank's North American network. The hackers had access to the data of about 200 thousand credit card holders, of which they were able to see names, account numbers and email addresses.
Citi said the hackers failed to get at other information such as dates of birth, social security numbers, security codes and card expiration dates.
The Bank has announced through a spokesman that “only 1% of accounts have suffered a breach. For the safety of these customers we will not disclose any other details, but we are putting in place more advanced procedures to prevent the recurrence of events of this type".