Since EP3 it's possible to follow a user into a dungeon.
There is one hint you can see if a invisible GM is around you: Hit the key to select next target (middle mouse button) multiple times. You can read it's name if you're lucky.
But in most of the time this will be too late, when doing AoE or standing in a wall.
If you're fit with scripts you can scan for objects with names like this "[??]*" and disconnect, but If a GM follows you into a dungeon he already has your ID.
UW bans? 11/07/2012 - DarkOrbit - 13 Replies there are stages? when bans are given?
Bans 02/17/2011 - Need for Speed World - 7 Replies Anyone got banned?
From what I heard, EA/BB are not very strict so there is very good chance of not getting banned.
And if you buy Boost they wont ban.
ip bans??? 02/20/2008 - Dekaron - 2 Replies did the new private server ban north american ips or am i the only one who can no longer connect?