The file was left entirely unprotected - no encryption, no password, no safeguards - just a plain text document holding millions of sensitive data entries.

Sensitive information including logins to social media accounts was among the data exposed in what some believe is the largest breach in U.S. history.

A newly discovered trove of stolen login credentials may represent the largest data breach in history, with billions of usernames and passwords now circulating online. Researchers with Cybernews uncovered more than 16 billion records spread across 30 databases,