>>>Hi,
>>>
>>>In a program that uses Sing-Factor Authentication (user ID and Password) I understand that each ID has to be unique. Does each user Password have to be unique too or duplicates are allowed?
>>>
>>>TIA
>>
>>If you make a unique password, alerting the user that that password is used by another user,
>>indirectly you're helping to get into other people's homes.
>
>LOL!, and the system can even tell you: Hey! your password is already used by John! :D
>
>Could be funny xD

Sure. We do not put limits to providence