Just happened on Empires Main Server (map urbanchaos): Suddenly most players stopped to move. Only six players were able to continue playing.
The map was UrbanChaos, not District. I guess it was just a mass disconnect due to connection issues. The server didn't even show up in the list afterwards.
CSDKPlayer::ClientCommand(). I even thought some time ago what would happen if I had removed it but Empires uses it for its stuff. And the second thing is that it's in the engine.
The bad thing is that such thing as a hardcoded cl_restrict_servercommands doesn't exist in emp. Thereforce it is possible to abuse people hardcode, but it also opens some options for server side modification.