Analysing the alleged Minneapolis police department “hack”
> it's extremely unusual to see the same email address with multiple different passwords in a legitimate data breach as most systems simply won't let an address register more than onceI've actually built a system which did this years ago, over our initial protestations, and the reasoning went like this:Our client (this was a white label product) has lots of elderly couples as customers, these are our end users and although they're on the Internet (makes sense, this is after all a web site you've white labelled so if you have customers without Internet that's a red flag right there) they only have one email address between them. So some end users want two accounts, but with one email address.This made the login procedure a bit hairy and obviously there are scary corner cases for things like change password (Alice decides to use the same password as her husband Bob, now we can't tell their accounts apart!) but we felt that arguing with clients about why they should do Single Sign On (and thus eliminate the separate login for our white label product altogether) was more valuable than trying to change old people's minds about what constitutes a reasonable thing for two people to share.