Some English EU realms are overrun by people that don't speak English. Trade chat is often dominated by unidentified (East-European?) languages.
Now don't get me wrong here, this isn't about bashing others! Many of these players are very friendly and will chat in English once in group with them.
It's just that they completely overtake certain realms and turn them into their own language-realm in major chat channels.
A possible "fix" would be to segregate even more realms into different languages, like it's already done for Germans, French and Spanish players.
Could this work? Or should Blizzard really enforce English in chat channels if you play on English realms?