exchange commission filed civil fraud charges today against two former c.e.o.s and form other ex-officials of fannie mae and freddie mac, the mortgage giants. they're accused of misleading investors about risky mortgage loans. wyatt andrews, now, with that. >> reporter: they were two of the most important players in the subprime mortgage meltdown. according to the s.e.c., richard syron, then c.e.o. of freddie mac and daniel mudd former chief of fannie mae committed fraud, misleading investors on the risks they were taking in subprime mortgages and down playing the hundreds of billions put at risk, all of it backed by taxpayer guarantees. robert khuzami is the chief of enforcements at the s.e.c.. >> fanny, freddie and their executives sought to maintain the illusion that the business involved minimal and manageable credit risk. >> reporter: for example, in 2007 with fanny aggressively buying subprime loans and with congress concerned about taxpayer losses, the s.e.c. says mudd gave the house a low ball figure he knew was fault. >> as a result, our exposure was minimal, less than 2.5% of our