very much related to PvP, PK, and thieving as well as general gaming. A player could potentially logoff of the game when things get rough. And then you have players appearing and disappearing all the time.
This must be dealt with, or a thief may loot and logoff. The disappearing thief... how impossible to catch.
In everquest they solved this by requiring you to camp before you logoff. As I detest nearly everything about everquest, I pray we do not mimic this.
Although, preventing logoff at certain times seems important. Such as when the arm of a thief is being held by its \'mark\'.
Also, just for the purpose of appearance, it would be nice to see a player logoff by walking through a portal he created... instead of simply vanishing.