One of the thing of this "online control" is the usage of the central character vault thingy, so that various servers can impose some regulation on the characters they have playing on the server at the same time as allowing the players to use the characters on other servers.
It will mean very little to a LAN game unless somebody wanted to use his vault character.
There is proberly else thing connected to this "checking" also though...
Enjoy your multiplayer experience, and remember to roleplay it, much more fun
