This Â short TED talk Â might convince you to redo some or all of your passwords. Lorrie Faith Cranor studied thousands of real passwords to figure out the surprising, very common mistakes that users â€” and secured sites â€” make to compromise security. And how, you may ask, did she study thousands of real passwords without compromising the security of any users? That’s a story in itself. It’s secret data worth knowing, especially if your password is 123456 .