Data Brokers and the Sale of Data on U.S. Military Personnel|Sherman et al. 2023 [pdf]

All the well-known trackers; Oracle, Equifax, Experian...

"Broker 5 sent us an Excel file with around 740 available variables for purchase within its “core” consumer database. Broker 7 emailed us a 31-page brochure detailing around 400 variables available for purchase. [...] Broker 4 likewise sent an Excel file of 475 variables available for purchase."