Businesses throughout the US state of California are being encouraged to carry out a security audit and make sure their systems are up to scratch, as 2.5 million data have been compromised since 2010.
Attorney-general Kamala Harris explained that last year alone, 1.4 million of these attacks occurred, many of which could have been averted.
Pressure is growing on companies to encrypt their data, as the figures also showed that an average of 22,500 people were impacted in some way by each data security incident.
In a statement, Harris said: "Data breaches are a serious threat to individuals' privacy, finances and even personal security.
"Companies and government agencies must do more to protect people by protecting data."
She also emphasised the need for companies to train employees and contractors in data security matters, especially in the retail industry, which reported the most incidents in 2012.
More than half (56 per cent) of the incidents involved Social Security numbers, putting large numbers of people at risk of identity theft.
Furthermore, 55 per cent were the result of intrusions by outsiders or unauthorised insiders, while the other 45 per cent were because companies had failed to put the appropriate security measures in place.