The attacker may already have the answer
The Federal Trade Commission explains that stolen usernames and passwords can be tried against other accounts. Reusing the same combination gives that attempt a chance to work. A password can be hard to guess and still be dangerous to reuse once it has been exposed. [1]
Make each account a separate problem
For accounts that need passwords, NIST recommends a password manager. These tools generate and store long, unique passwords so you do not have to memorize each one. The practical goal is a different secret for each service, rather than one clever secret carried everywhere. [2]
Protect the place that holds them
NIST also points out that the manager itself needs a login and recommends choosing one that supports multifactor authentication: a login check using more than one kind of evidence. The manager’s convenience does not remove the need to protect access to it. [2]
Start with the accounts that matter most
The FTC advises adding two-factor authentication first to sensitive accounts such as email and financial services. If credentials are exposed in a breach, it advises changing the password promptly. Unique passwords address reuse; extra authentication adds another layer. [1]
Go a little deeper
Optional reading · about 1 more minute
A two-account thought experiment
Imagine a hobby forum and an email account sharing the same username and password. If that pair leaks from the forum, someone can try it at the email service. Now imagine each account has its own password: the forum’s secret no longer supplies the email password. This hypothetical example isolates reuse; it is not a claim that the email account has no other risks.
Separate three different questions
Our suggested review asks: Is each password unique? Can I recover access if I lose a device? Is an additional authentication method enabled? Treat these as separate checks. A reassuring answer to one should not silently stand in for the other two.
Original sources
Attributed synthesis, not original reporting. Examples labeled hypothetical or illustrative are explanatory. Reviewing a source does not independently validate its findings.
- FTC: Use Two-Factor Authentication To Protect Your Accounts ↗
September 2022 consumer guidance reopened September 14, 2026. Credential reuse, breach response and account prioritization reviewed; no current incident-rate claim.
- NIST: How Do I Create a Good Password? ↗
Password-manager and multifactor-authentication explanations reviewed September 14, 2026. No product ranking or numerical cracking-time claim used.
