You know how to make account sharing really onerous? Mandatory MFA (and don't allow sane solutions like TOTP or U2F enrollments). Or, you could mandate that ev

You know how to make account sharing really onerous? Mandatory MFA (and don't allow sane solutions like TOTP or U2F enrollments). Or, you could mandate that every account must use a SSO identity service, like Google/FB/Amazon/Twitter. Then small-time account sharers would need to consider whether they should give away keys to the kingdom as well.