After the Equifax breach, experts are puzzled about why data from 143M Americans didn't end up for sale online; one theory suggests a nation-state is using it (Kate Fazzini/CNBC)

Kate Fazzini / CNBC:
After the Equifax breach, experts are puzzled about why data from 143M Americans didn't end up for sale online; one theory suggests a nation-state is using it  —  - Equifax's data breach on Sept. 7, 2017, stunned markets and American consumers, but where the data of those 143 million people disappeared to has remained a mystery.