In other words, the fact that it is cryptographically derived from the email is irrelevant. What makes an email PII is not the content of it, because outside of

In other words, the fact that it is cryptographically derived from the email is irrelevant. What makes an email PII is not the content of it, because outside of some rare names or personal/family domains, knowing John Doe who uses Yahoo is not enough to identify a person. What makes email address and other unique identifiers like a hash of an email PII is that the given universally unique composition of letters and symbols is associated with a person. john.doe@example.com -> a facebook profile -> Legal Person 836f82d......b39577f -> a facebook profile -> legal person. For identifying a person both 836f82d......b39577f and john.doe@example.com are the same.