Make a level 1 alt. Call him something like "XXXbank" or something of the likes. Your goal is to make your name not arouse suspicion when a level 1 is buying mats or items for level 60's...
Carrying on...
Walk into a capital city. You'll see something like this:
2.[Trade][Luckybastard]: WTS [Krol Blade] [Elemental Mage Staff] PST!!!
2.[Trade][Farmer]: WTS [Dark Iron Bar]x10 5g each!!
1.[General][Knowitall]: All I'm saying is that moonfire is really overpowered
2.[Trade][Bankzor]: SELLING LARGE BRILLS PST!!!
4.[Looking For Group][Noob]: SNAKES ON A PLANE LOLZ
Heres the Scam:
Whisper anyone and everyone to COD you the item they are selling. Make sure not to make others know you are buying a lot of stuff. Only whisper the person once, and don't say anything in the trade channels about "BUYING ALL UR EPIX".
Heres the cache: If the person is a noob, then they will forget to put the amount of gold owed in the COD box. Meaning they just sent you a free purple, or other expensive piece.
Which also means that since its their mistake and you didn't actually scam them, that the item itself is free, and completely clean. They can page a GM all they want but the item is yours to keep.
And if they put the amount? Either be mean and wait 3 days for it to automatically return, or just click return. They'll probably assume that you couldn't afford the item.
Anyways, this scam solely depends on the amount of idiots on your server, along with all the noobs and people who are just plain forgetful. And if you skipped over the part where I said its unbannable... Well I just said it again...
Also, I would reccomend a whisper managment mod to keep track of whispering 10+ people at a time. It really helps.