[cshesse]

Maybe it should be "Username or password in use"

[sesqu]

The sad thing about that is that there have been actual applications with actual users that require unique passwords.

[bornhuetter]

I was wondering recently if someone had ever done this. Do you have any examples/links?

[sesqu]

TDWTF has several anecdotes. Try this, for one: http://thedailywtf.com/Articles/Uniquely_Secure.aspx

[bornhuetter]

Thanks, that's hilarious. I can see someone thinking that unique passwords are a way to make sure that people aren't overusing common passwords - and not realizing that you are implicitly letting everyone know what passwords are currently in use.

[jessejmc]

Guild Wars 2 is like this. I was trying to use the same password for two accounts and received “Unavailable password. You or someone else has used it before."

[RyJones]

Amazon used to have accounts where the email address was common, differing only in password. They were only phased out in the last year.

[nthj]

POST /users HTTP/1.1

username=johnsmith&password=297324khd239723khad7823hksd7gh1h