[mopsi]

Absolutely, and e-mail or Paypal account name too. Neither of them are trivial to change. If you try to create a new account for each thing at a generic mail provider such as Gmail, your accounts will be shut down by automatic abuse filters. If you roll your own domain, then, well... the domain becomes the foreign key.

[Perseids]

The solution to this is unlimited true email aliases as e.g. StartMail [1] and Fastmail [2] provide. I wish this was more common place for email provider. Besides the front up cost of developing / setting up the solution, email aliases have the marginal cost of one small database row per alias. And it would be such a boon for privacy.

[1] https://support.startmail.com/hc/en-us/articles/360007297457...

[2] https://www.fastmail.help/hc/en-us/articles/360060591073

[seng]

Would using a separate service email accounts help mitigate issues? [e-mail], then [e-mail], [e-mail], etc? That way my primary email would stay private and will used only for email, not for identity.

[sammax]

Your private email that you don't use for signing up anywhere is irrelevant except for phishing and spam. Your secondary email address will become the foreign key that is used to correlate the datasets from everywhere you signed up with it. The +tags can just be removed since it is known how they work. Might give you a small protection against attackers who don't know about email address tags.