More than half a billion identities found exposed since last August.
Hackers were responsible for only half of data breaches within the last year, according to security firm Symantec.
Accidental public disclosure accounted for almost a quarter of the breaches recorded in the company's most recent report on the past year, with a fifth attributed to theft or loss of a device.
Ben Nahorney, cyber security threat analyst at Symantec, said: "Hackers continue to be responsible for 49 percent of data breaches over the last 12 months, most often exposing real names, government ID numbers, such as Social Security numbers, and home addresses in the data breaches."
567 million identities were found to have been exposed in the last year, with 71% of breaches revealing real names, almost half social security numbers , and 43% home addresses.
The largest data breach reported in July leaked 900,000 identities, though compared to the company's data over the year it was a quiet month.
Spears fishing most often afflicted groups with 2,500 or more employees at more than a third of attacks, though those with 250 or fewer workers were not far behind.
"The .doc file type continues to be the most common attachment type used in spear-phishing attacks, followed by .exe files," Nahorney said.
Source: Company Press Release