More than 100 million credit card applicants had their personal information compromised in the Capital One hack announced, illustrating once again just how vulnerable consumer data can be even for the most security-minded organizations.

 

The hack, one of the largest ever against a financial services firm, comes just days after the credit-reporting company Equifax reached a $700 million settlement with U.S. regulators over the high-profile 2017 cyberattack that exposed the data of 147 million people.

FBI agents arrested a Seattle software engineer, Paige A. Thompson, on accusations of computer fraud. The bank says the hack exposed 140,000 Social Security numbers and 80,000 bank account numbers, as well as credit scores, balances, and personal information such as addresses, birthdays and contact information. Roughly 6 million Canadian customers also were affected, Capital One said.