Today after my login the game screen I noticed this account (do not ask me to write his/ her nickname , it's impossible )
Like this account there are several users who choose symbols to create their nicknames or letters from other languages than english (like korean , chinese etc).
This can cause serious troubles. I do not want to post what kind of troubles in order to not give bad ideas.
My suggestion is to put some restrictions in the registration form which must give ability to create account using only characters from english and numbers , nothing else.