What does "Remove All Trusted Devices" mean?

By clicking "Remove All Trusted Devices", we'll require your username, password, AND a verification code (that we send to your phone or email) to sign in on any computer, even if you've used that computer to access your account in the past.

When you sign in, you can choose whether or not to have us "remember" the device you're using. On remembered (trusted) devices, you only need your username and password to sign in.