It's known that hundreds of millions of debit and credit card records were stolen in 2013, but the problem could be a whole lot bigger than we imagined. 

Looking over the 500 breaches listed on the Privacy Rights Clearinghouse Chronology Data Base, the folks at Online Trust Alliance say they found more than 740 million records that were exposed to data thieves last year.

That could be just the tip of the iceberg, since USA Today reports many of the listed data breaches don't put a number on the records actually stolen.

But, with just the numbers we do have, the Clearinghouse research shows thefts of credit card data, including social security numbers, was five times greater in 2013 when compared with 2012.

More information on specific data breaches for past several years can be found at Privacy Rights Clearinghouse Chronology Data Base.