>>>There are also few cases, when the same login and password were used twice. Recently somebody from China became a person from OH.
>>
>>Username are unique. So, what happened is someone thought his username was something while it was belonging to someone else.
>
>I don't know, but may be this particular case needs to be resolved. He should change the way, he login to be correctly identified.

I don't know anything more about this case. But, it was just a question of luck that someone thought that his username was something and then he tried a password and that worked.