<chuckles> you guys need to chill a bit.Let's not make this personal.
Yes, the MAC address never leaves the local network.
But...
It is possible for the WoWclient to read the MAC address of the machine on which its running, and periodically send that information to the WoWserver-side session manager captured in a WoW data packet (unlike the IP packets the MAC address is normally used in). This is how the MAC address might be associated with your session/machine, not because it escapes the network as part of the IP datagram.
You'd have to pull out WireShark or something and examine the escaping WoW data packets to see whether or not this was actually being done. This is just but one form of data-mining that Bliz has at their disposal where they can perform WoWserver-side only analysis to catch botters, if they wanted to.
Just another spin,
chinajade
I've checked it over and over and this proves to be untrue, or they are not yet reading mac addresses at this current time