[cyrusaf]

It's possible their truncate also restarted the sequence: "TRUNCATE TABLE users RESTART IDENTITY;"

https://stackoverflow.com/questions/13989243/sequence-does-n...

Although, I am confused about how sign ins created new users. When they say sign ins, do they mean new accounts?

[catfood]

Yeah they must mean new accounts, if not then I'm lost. I guess it could have reset autoincrement but they said it didn't. The only other thing I can think of is that the signed token that's put in localStorage is sent to the server like "someuser|sometoken", the server inspects sometoken, says it checks out, then takes the client at its word that it's someuser.

[inopinatus]

A sign-in can result in an automatic account creation when using federated identity.