3 ms·

I mean unique as far as your end is concerned. Short of very invasive technology, there's no way to stop people from sharing a user token if they choose to do s

• zAy0LfpBZLC8mAC 10y ago
  Except, it's not a "user token", it's an address. It's as much a user token as a postal address or a telephone number is a "user token": not at all. It's a way to contact a person, not a way to identify a person. Just because you can enforce that only one person with a given postal address can create an account with your service, doesn't make it an inherent "user token".
  • throwanem 10y ago
    Yep. I designed a system once around the assumption of a 1:1 mapping between people and email addresses. I will never design another system that way.
• Kadin 10y ago
  Sure, but what if two humans share an email address, but both of them want to sign up for your game/service/whatever independently? This is a fairly common situation if you are (say) designing a game that might appeal to kids. Or old people. If you block that, you're going to lose users. Either because they just can't sign up at all, or because there's too much unnecessary friction in requiring someone to go out and sign up for an email address just to register for your service.