"When I see something like this, I want to scream," says Florida identity theft expert . "It's like a goldmine of information."

Companies in Sony's position typically respond by offering affected users a year of free credit monitoring--something any consumer in the U.S. is entitled to already. "To me, that's nothing," Richardson says. "Thieves are sitting back laughing at that."

Sophisticated data thieves have moved beyond stolen credit cards and use personal info like birthdates and home addresses to open bank accounts, obtain medical services or collect other people's unemployment checks. The fact that many of Sony's 77 million compromised accounts likely include teenagers and young adults makes it worse, she says, because they may not know their data was compromised for years, compounding Sony's potential liability.

"What happens next depends on how much damage comes from it," Richardson predicts. "It's going to cost Sony billions, is my guess."

Sadly, it falls to individuals to cancel credit cards, change passwords and watch their email and other communications carefully, and perhaps think twice about typing in reams of personal info on each website that asks for it. If you're looking for help try our .