Bug with Greek Lanugage

Hello

There is some guy using some bug with greek language.
He is coping a letter from greek language and doing like first letter greek language and others are normal ( like Sadfaffel ) and then he changes the name again but to something else and when he does that then when you go to view topic then all sadfaffel names change to something he changed his name to.
And when he does that greek thing then quotes change to Sadfaffel :etirW, Not the text but only the Write part.

Greek language = https://en.wikipedia.org/wiki/Greek_alphabet

Can you fix this?

Thank You
Sadfaffel