ok since this is flawed, and takes a lot of chance ..... and i'm really high. Here's how it all goes.
If you're going to try to scam someone you need to understand, most people don't give out their account info. noobs do. But we don't want to scame noobs, it's a waste of time. The trick is this.
first we get the IP's we need to keep it all organized. on official wow servers the chat is channeled over to another box. To keep the strain off the world server. Bind a packet sniffer on to your own computer, and shut down every program that connects to the net,.
This keeps the list of IP's short. Open up the command prompt (for noobs it's start>run>"cmd" 'enter' and type netstat-a. This will show you all of the ports transmitting data, in and out. weed out the normal windows junk, and you should be left with the wow chat server IP. (to get the logon server sniff and logon then stop and search for your login or pass and you've got the IP).
Rebind your packet sniffer to the chat server, and start sniffing. Now go back into wow and type messages via /w to your target in game, try to write something that would stand out. not lawl or something lame that EVERYONE says. even something like "that raid fookin sucked" you can search through the list of packets captured for your text and you have you're packet. But you'll have it for where it went being both your IP and your targets. clear out yours and you have you're targets IP.
Now you're set to bind a sniffer to his computer. leave it there for a while, you need them to log out and in again, so it may take up to a day. when you're ready, stop sniffing and search the data for the logon server IP. the data in those packets will be some junk, like the handshake, lock and key shit, and the part we want ..... their user name and password.They'll have no clue who the **** took it :P