Hackers who attacked Citigroup last month stole millions of dollars from customers' credit card accounts.
Citigroup says its customers lost 2.7-million dollars in the cyber attack.
The hackers got access to more than 360 thousand accounts.
Citigroup executives say customers are not liable for the losses.
This is just one of several recent high-profile security breaches.
Video game maker "Electronic Arts" reported Friday that hackers breached a server linked to a message board and stole customer information.
Sony was subjected to major hacks in April and May.