Take laptop A. With it, use a passkey to log into a website. Sync passkey with the FAANG of your choice. Destroy laptop A.
Take laptop B. Log in to your FAANG of choice, syncing passkeys locally. Use laptop B to log into the same website.
Your FAANG of choice saw much more than a public key, for that to be possible. That might have been encrypted by something like your password to the FAANG, but still, it's the opposite of a tamperproof HSM.
