Useful to me? None. Useful to spammers? Half a billion emails is very useful. Useful to hackers? Hundreds of millions of records. Useful for fraud? Hundreds

Useful to me? None. Useful to spammers? Half a billion emails is very useful. Useful to hackers? Hundreds of millions of records. Useful for fraud? Hundreds of millions of records. Useful for data-mining and intelligence? All of them. Many banks don't issue new debit/credit card numbers, they just change the expiration (the 3 digit code is rarely used from my personal experiences). It's easy to brute force the expiration. SSN numbers and security questions can allow access to many accounts. Figuring out password hashes (lots of methods) is sometimes easy, sometimes hard. Bank account numbers rarely change, damage can be done with these. How many people use their real information online? Most. How many use secure passwords and change their passwords ever/enough? Few. The LexisNexis breach alone is a disaster, they're basically data-miners with exclusive access to personal details.