Not long ago, a breach that compromised the data of a few million people would have been big news. Now, breaches that affect hundreds of millions or even billions of people are far too common. About 3.5 billion people saw their personal data stolen in the top two of 15 biggest breaches of this century alone. The smallest incident on this list involved the data of a mere 134 million people.
CSO compiled this list of the biggest 21st Century breaches using simple criteria: The number of people whose data was compromised. We also made a distinction between incidents where data was stolen for malicious intent and those where an organization inadvertently left data unprotected and exposed. Twitter, for example, left the passwords of its 330 million users unmasked in a log, but there was no evidence of any misuse. So, Twitter did not make this list.
