3 ms·

Neither are SSNs, but hey...

• aneesh 18y ago
  Well, they're not completely ineffective. How many people do you know that have two or more SSNs? How about multiple email addresses?
  • tomsaffell 18y ago
    I've heard of it going the other way, i.e. one SSN maps to multiple people (or at least multiple names).
  • jshen 18y ago
    well there are two different issues that overlap a good deal. 1. wanting a way to uniquely identify a user that is easy for the user to remember (email works great) 2. wanting a way to prevent users from creating duplicate accounts Using emails works great for 1 and is a decent low bar for 2. There are no good answers for 2 so using an email address is the best I have seen.