The Most Common Security Mistake
According to security surveys, over 60% of people reuse passwords across multiple services. This single habit is responsible for more account compromises than any other factor, because it allows attackers to turn one breach into access to many accounts.
How Credential Stuffing Works
When a data breach exposes email and password combinations, attackers don't just use them on the breached service. They systematically test those credentials against hundreds of other services — a technique called credential stuffing.
Automated tools can test millions of credential pairs against popular services in a matter of hours. If you used the same password on the breached service and your email account, banking site, or social media, attackers will find it.
Real-World Consequences
The Dropbox breach of 2012 was caused by an employee reusing a password from LinkedIn. One person's password reuse led to the exposure of 68 million accounts.
This pattern repeats constantly:
- LinkedIn breach credentials used to access corporate email
- MySpace passwords used to compromise active social media accounts
- Gaming site breaches leading to stolen in-game items worth real money
Why People Reuse Passwords
Most people know password reuse is risky, but do it anyway because:
- It's easier to remember one password than dozens
- They underestimate the risk ("who would target me?")
- They don't know about password managers
- They assume breaches won't affect them
The Solution: Password Managers
Password managers solve the reuse problem by:
- Generating unique, strong passwords for every service
- Remembering all your passwords so you don't have to
- Auto-filling credentials so unique passwords aren't inconvenient
- Alerting you when stored passwords appear in breaches
Check Your Exposure
Use LeakedSource to see how many breaches your email has appeared in. If any of those breached passwords are ones you've used elsewhere, change them immediately.