: Usernames and passwords for their internal systems.

Experts later clarified that while the "2.9 billion" figure likely included many duplicates and deceased individuals, the scale remained historic. Unlike the , which stemmed from a software vulnerability, the NPD incident is frequently cited as a cautionary tale about directory listing vulnerabilities and the dangers of storing sensitive backups on internet-facing servers.

The breach wasn't necessarily a complex hack but a critical oversight. A security researcher discovered that NPD had left a zip file—often identified as index_breached.vc.zip or similar variants—publicly accessible on their website. This file contained:

Following the leak, multiple class-action lawsuits were filed against Jerico Pictures Inc. for failing to secure the data. You can find technical post-mortems and security analysis of the breach on platforms like the Huntress Blog or specialized security news sites like Risky Business .

: Details on how their databases were structured and accessed. The Dark Web Leak