Why must everyone have unique email addresses?
In order for us to prove account ownership and verify identity we must send correspondence to the email address on file. If more than one user shared an email address we would have no way of verifying a user's identity in some situations. In a worst case scenario, someone with malicious intent, could register an account with your email address and then claim to be you if we were allowing multiple people to have the same email address. For these security reasons we implement this strict policy to protect you, your identity, and your data.