C. You agree that you will not :

iv. allow players who are playing characters aligned with the "Alliance" faction to chat or otherwise communicate directly with players who are playing characters aligned with the "Horde" faction, or vice versa;
Source: http://www.wow-europe.com/en/legal/termsofuse.html

It's in the EU version of the Terms of Use, I read it when the game restarted, was in the last of te 3 screen you will have to press accept.

Seems it is indeed not allowed to have 2 chars running, 1 in each faction ? I'm gonna contact a GM when I get home tonight. Would be a stupid reason to get banned / suspended :thumbdown: