Governments lost 307 million records to breaches in 2015

It's not just the Office of Personnel Management breach -- cyberattacks targeting personal information exploded globally in 2015. According to Gemalto's just-released Breach Level Index, more than 707 million records were compromised in 1,673 significant breaches worldwide last year, and 53 percent of those incidents involved identity theft.

Not all those incidents targeted government, of course, but Gemalto -- an international digital security firm based in the Netherlands -- found that 307.1 million of the compromised data records came from the public sector. That marked a 476 percent increase over 2014.

OPM's breach, which the index scored a 9.6 on a scale of 10, was not even the largest or most severe government incident. Hackers targeting Turkey's General Directorate of Population and Citizenship Affairs compromised 50 million records, resulting in a Breach Level Index score of 9.9. (The breach of U.S.-based Anthem Insurance topped the index with a perfect 10.)

And U.S. targets in general drew the lion's share of attacks -- 1,222 of the 1,673 documented in 2015.

"It is important to keep in mind that not all breaches are equal in terms of the level of severity and damage that they can bring," Jason Hart, Gemalto's vice president and CTO for data protection, said in a statement announcing the 2015 index. And last year, he said, "criminals shifted to attacks on personal information and identity theft, which are much harder to remediate once they are stolen."

See the Breach Level Index here.