How Did This Happen and Why Are There 16 Billion Passwords Leaked?

This kind of massive password compilation usually comes from:

1. How Did It Happen?

Decades of accumulated breaches: Most of these passwords come from thousands of different data breaches (such as attacks on social networks, email services, games, and shopping sites) over the years.

Compilation by criminals or researchers: Hackers or cybersecurity experts gather leaked databases into a single file (a "mega leak") to make access or analysis easier.

Sale or public release: This data may be sold on the dark web or leaked for free to be used in further attacks.

2. Why So Many Passwords?

Password reuse: Many people use the same password across multiple sites. If one service is hacked, criminals test those credentials on other platforms (credential stuffing attacks).

Insecure storage: Companies that fail to encrypt passwords properly make large-scale leaks easier when they’re hacked.

Old passwords: Many of these passwords are from years ago but are still active in accounts that haven’t been updated.

Impact

Account takeover risks: Criminals use these passwords in credential stuffing attacks to break into accounts.

Fraud and scams: Leaked data is used for phishing, extortion, and identity theft.

How to Protect Yourself?

✅ Use unique passwords for every site/app (a password manager helps).

✅ Enable two-factor authentication (2FA) whenever possible.

✅ Check if your data was leaked on sites like Have I Been Pwned.