MALVEAUX: Citigroup is tightening its online security after hackers got a look at the information of some 200,000 credit card customers. Citigroup says that no important information was compromised, but CNN's Brian Todd found out that that is not necessarily the case.</s>BRIAN TODD, CNN CORRESPONDENT (voice-over): If you do any banking online, you will see that reassuring template -- here is how we will protect your money, your identity. Citigroup has got it, but Citigroup just got hacked. The company says someone accessed the personal information of about 200,000 North American customers. It won't say how much money was lost. The hackers didn't seize Social Security numbers, dates of birth or card security codes, the company says, but did view customers' names, account numbers and contact information. (on camera): Can they still do damage getting names, account numbers, contact information?</s>MARK RASCH, CYBERSECURITY CONSULTANT, CSC: They can try to poach customers from Citibank. But more importantly, they can use that information to try to trick Citibank tellers or other operators into believing that they are the actual customer.</s>TODD (voice-over): Mark Rasch is a former cybercrime prosecutor at the Justice Department. He says the banks' built-in protections only go so far. (on camera): On the same page of its Web site where it says how you are protected, Citigroup says it uses 128-bit secure sockets layer encryption technology, the most widely used method of securing Internet transactions available today. Sounds impressive, but can it really protect you? What does this even mean?</s>RASCH: What SSL is, it means that from your browser, from this window here, to their computer, there is like a secure pipe that's really hard to break into. It doesn't mean anything about -- it's like driving to the bank. When you're driving to the bank, you're secure. But once you get inside the bank and engage in a transaction, it doesn't mean anything about the security of that transaction or the files when they're stored in their filing cabinet.</s>TODD (voice-over): Brian Todd, CNN, Washington.
200,000 Citigroup Customers Hit in Hacking