1) An expert street thief, who has people buying his stolen goods.
2) Someone who makes/sells pirate copy DVDs, CDs, and other things like that.
3) To steal out of a bag, handbag, pocket, etc.
1) I'm going to get some stuff off the yanksmith.
2) The yanksmith in the Shopping Centre has the new FPS game from Nintendo.
3) Damn it! I've been yanksmithed!