What do Sega, Citigroup, Sony and InfraGard have in common? All experienced data breaches earlier this summer. Some were the work of malicious or politically motivated groups, such as the attack on government contractor InfraGard by LulzSec. More often, criminals are trying to obtain information that can be used to steal money, either from the targeted company or its customers or suppliers.

In the Sony attack, hackers obtained over a million customers' passwords, e-mail addresses, phone numbers, dates of birth and other information.

But the risks to companies go way beyond the defrauding of customers, says William Katz, a partner at the Texas law firm of Thompson & Knight.