You're not required to contribute with your amazon e-mail address, and I see a lot of people who don't due to inertia or because they want to avoid tying their identity their employer.
Agreed it's not perfect, and that's why I included my methodology and asked if anyone has a better source since less substantiated claims are being quoted:
You're not required to contribute with your amazon e-mail address, and I see a lot of people who don't due to inertia or because they want to avoid tying their identity their employer.