Calif. AG: Data hacks stole personal information on 18.5 million California accounts in 2013

The number of Californians whose personal data was hacked last year jumped sixfold to 18.5 million accounts and as many as one-third of those people will become victims of fraud, says California Attorney General Kamala Harris, in a new report on data breaches in the nation's biggest state.

Retailers, banks, health care providers and other organizations reported 167 different breaches in the state during 2013. That's up 600 percent from the 2.5 million accounts hacked in 131 breaches in 2012, and represents nearly half of the state's 38 million residents. The alarming increase in malicious hacking and accidental leaks due to poor information security was partly due to breaches at Target stores and Living Social, an online marketplace. Even without those two incidents, the number of customer accounts exposed by other hacks jumped 35 percent last year.

"Data breaches are a serious threat to Californians' privacy, finances and even their personal security," Harris says in the report, which she plans to release at a press conference Tuesday in Los Angeles.

As many as one third of people whose information is exposed in a data breach will subsequently suffer some kind of fraud, Harris adds in the report, citing estimates by Javelin Strategy and Research, a California firm that tracks financial industry trends.