[multidim]

>What am I supposed to do whenever I'm involved in a new breach? Burn all my accounts and start again?

If you reuse passwords, then change your passwords for all the accounts that use the breached password. Hopefully, it'll spur you to start using a password manager so you can easily have strong, unique passwords.

If you don't reuse passwords, then change your password for the breached account. Sometimes services don't tell you about breaches and it is HIBP that first informs you about the breach.

If there is some email address that you really, really don't want bad guys to know about (perhaps a dedicated email address for your important financial accounts), then it helps you know when to switch to another email address.

HIBP helps you know how often a service has been breached in the past, and that might help guide what services you want to use/not-use in the future.